find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21...

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Find each product. 1. (x + 5)(x + 2) SOLUTION: 2. ( y 2)( y + 4) SOLUTION: 3. (b 7)(b + 3) SOLUTION: 4. (4n + 3)(n + 9) SOLUTION: 5. (8h 1)(2h 3) SOLUTION: 6. (2a + 9)(5a 6) SOLUTION: FRAME eSolutions Manual - Powered by Cognero Page 1 8 - 3 Multiplying Polynomials

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Page 1: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 1

8-3 Multiplying Polynomials

Page 2: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 2

8-3 Multiplying Polynomials

Page 3: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 3

8-3 Multiplying Polynomials

Page 4: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 4

8-3 Multiplying Polynomials

Page 5: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 5

8-3 Multiplying Polynomials

Page 6: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 6

8-3 Multiplying Polynomials

Page 7: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 7

8-3 Multiplying Polynomials

Page 8: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 8

8-3 Multiplying Polynomials

Page 9: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 9

8-3 Multiplying Polynomials

Page 10: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 10

8-3 Multiplying Polynomials

Page 11: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 11

8-3 Multiplying Polynomials

Page 12: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 12

8-3 Multiplying Polynomials

Page 13: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 13

8-3 Multiplying Polynomials

Page 14: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 14

8-3 Multiplying Polynomials

Page 15: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 15

8-3 Multiplying Polynomials

Page 16: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 16

8-3 Multiplying Polynomials

Page 17: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 17

8-3 Multiplying Polynomials

Page 18: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 18

8-3 Multiplying Polynomials

Page 19: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 19

8-3 Multiplying Polynomials

Page 20: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 20

8-3 Multiplying Polynomials

Page 21: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 21

8-3 Multiplying Polynomials

Page 22: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 22

8-3 Multiplying Polynomials

Page 23: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 23

8-3 Multiplying Polynomials

Page 24: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 24

8-3 Multiplying Polynomials

Page 25: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 25

8-3 Multiplying Polynomials

Page 26: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

eSolutions Manual - Powered by Cognero Page 26

8-3 Multiplying Polynomials

Page 27: Find each product. · 2014-02-23 · (8h í 1)(2 h í 3) 62/87,21 (2a + 9)(5 a í 6) 62/87,21 )5$0(eSolutions Hugo is designing a frame as shown. The frame has a width of x inches

Find each product.1. (x + 5)(x + 2)

SOLUTION:  

2. (y − 2)(y + 4)

SOLUTION:  

3. (b − 7)(b + 3)

SOLUTION:  

4. (4n + 3)(n + 9)

SOLUTION:  

5. (8h − 1)(2h − 3)

SOLUTION:  

6. (2a + 9)(5a − 6)

SOLUTION:  

7. FRAME  Hugo is designing a frame as shown. The frame has a width of x inches all the way around. Write an expression that represents the total area of the picture and frame.

SOLUTION:  The total length is 2x + 20 and the width is 2x + 16.

Find each product.

8. (2a − 9)(3a2 + 4a − 4)

SOLUTION:  

9. (4y2 − 3)(4y

2 + 7y + 2)

SOLUTION:  

10. (x2 − 4x + 5)(5x

2 + 3x − 4)

SOLUTION:  

11. (2n2 + 3n − 6)(5n

2 − 2n − 8)

SOLUTION:  

Find each product.

12. (3c − 5)(c + 3)

SOLUTION:  

13. (g + 10)(2g − 5)

SOLUTION:  

14. (6a + 5)(5a + 3)

SOLUTION:  

15. (4x + 1)(6x + 3)

SOLUTION:  

16. (5y − 4)(3y − 1)

SOLUTION:  

17. (6d − 5)(4d − 7)

SOLUTION:  

18. (3m + 5)(2m + 3)

SOLUTION:  

19. (7n − 6)(7n − 6)

SOLUTION:  

20. (12t − 5)(12t + 5)

SOLUTION:  

21. (5r + 7)(5r − 7)

SOLUTION:  

22. (8w + 4x)(5w − 6x)

SOLUTION:  

23. (11z − 5y)(3z + 2y)

SOLUTION:  

24. GARDEN  A walkway surrounds a rectangular garden. The width of the garden is 8 feet, and the length is 6 feet. The width x of the walkway around the garden is the same on every side. Write an expression that represents the total area of the garden and walkway.

SOLUTION:  Let 2x + 8 = the width of the garden and walkway and let 2x + 6 = the length of the garden and walkway.

Find each product.

25. (2y − 11)(y2 − 3y + 2)

SOLUTION:  

26. (4a + 7)(9a2 + 2a − 7)

SOLUTION:  

27. (m2 − 5m + 4)(m

2 + 7m − 3)

SOLUTION:  

28. (x2 + 5x − 1)(5x

2 − 6x + 1)

SOLUTION:  

29. (3b3 − 4b − 7)(2b

2 − b − 9)

SOLUTION:  

30. (6z2 − 5z − 2)(3z

3 − 2z − 4)

SOLUTION:  

Simplify.

31. (m + 2)[(m2 + 3m − 6) + (m

2 − 2m + 4)]

SOLUTION:  

32. [(t2 + 3t − 8) − (t2 − 2t + 6)](t − 4)

SOLUTION:  

CCSS STRUCTURE  Find an expression to represent the area of each shaded region.

33. 

SOLUTION:  Find the area of the circle.  

  Find the area of the rectangle.  

  Subtract the area of the rectangle from the area of the circle.  

 

The area of the shaded region is represented by the expression 4πx2 + 12πx + 9π − 3x

2 − 5x − 2.

34. 

SOLUTION:  Find the area of the rectangle.  

  Find the area of the triangle.  

  Subtract the area of the triangle from the area of the rectangle.  

The area of the shaded region is represented by the expression 24x2 − .

35. VOLLEYBALL  The dimensions of a sand volleyball court are represented by a width of 6y − 5 feet and a length of 3y + 4 feet.   a.  Write an expression that represents the area of the court.   b.  The length of a sand volleyball court is 31 feet. Find the area of the court.

SOLUTION:  a.

 

The area of the court is represented by the expression 18y2 + 9y − 20.

  b.

  Substitute 9 for y in the expression for area to find the area of the sand volleyball court when the length is 31 feet. 

 

The area of the sand volleyball court is 1519 ft2.

36. GEOMETRY  Write an expression for the area of a triangle with a base of 2x + 3 and a height of 3x − 1.

SOLUTION:  

The area of the triangle is represented by the expression .

Find each product.

37. (a − 2b)2

SOLUTION:  

38. (3c + 4d)2

SOLUTION:  

39. (x − 5y)2

SOLUTION:  

40. (2r − 3t)3

SOLUTION:  

41. (5g + 2h)3

SOLUTION:  

42. (4y + 3z)(4y − 3z)2

SOLUTION:  

43. CONSTRUCTION  A sandbox kit allows you to build a square sandbox  or a rectangular sandbox as shown.  

  a.  What are the possible values of x? Explain.   b.  Which shape has the greater area?   c.  What is the difference in areas between the two?

SOLUTION:  a.  The value of x must be greater than 4. If x = 4 the width of the rectangular sandbox would be zero and if x < 4 the width of the rectangular sandbox would be negative.   b.

 

  The square has the greatest area.   c. Subtract the area of the rectangle from the area of the square.  

 

The difference in the areas is 4 ft2.

44. MULTIPLE REPRESENTATIONS  In this problem, you will investigate the square of a sum.   a.  TABULAR  Copy and complete the table for each sum.  

  b.  VERBAL  Make a conjecture about the terms of the square of a sum.   c.  SYMBOLIC  For a sum of the form a + b, write an expression for the square of the sum.

SOLUTION:  a.

 

   b.  The first term of the square of a sum is the first term of the sum squared. The middle term of the sum is two times the first term of the sum multiplied by the last term of the sum. The third term of the square of the sum is the last term of the sum squared.   c. 

 Then,

45. REASONING  Determine if the following statement is sometimes, always, or never true. Explain your reasoning. The FOIL method can be used to multiply a binomial and a trinomial.

SOLUTION:  Always; by grouping two adjacent terms, a trinomial can be written as a binomial (the sum of two quantities), and

apply the FOIL method. For example, (2x + 3)( x2 + 5x + 7) = (2x + 3)[ x

2 + (5x + 7)] = 2x(x

2) + 2x(5x + 7) + 3

(x2) + 3(5x + 7). Then use the Distributive Property and simplify.

46. CHALLENGE  Find (xm

+ x p)(x

m−1 − x1−p + x

p).

SOLUTION:  

47. OPEN ENDED  Write a binomial and a trinomial involving a single variable. Then find their product.

SOLUTION:  

Sample answer: x − 1, x2 − x − 1.

48. CCSS REGULARITY  Compare and contrast the procedure used to multiply a trinomial by a binomial using the vertical method with the procedure used to multiply a three-digit number by a two-digit number.

SOLUTION:  The three monomials that make up the trinomial are similar to the three digits that make up the 3-digit number. The single monomial is similar to a 1-digit number. With each procedure you perform 3 multiplications. The difference is that polynomial multiplication involves variables and the resulting product is often the sum of two or more monomials, while numerical multiplication results in a single number. Consider the following examples.  

49. WRITING IN MATH  Summarize the methods that can be used to multiply polynomials.

SOLUTION:  The Distributive Property can be used with a vertical or horizontal format by distributing, multiplying, and combining like terms.   Horizontal:                                                                             Vertical:  

         The FOIL method is used with a horizontal format. You multiply the first, outer, inner, and last terms of the binomialsand then combine like terms.  

    A rectangular method can also be used by writing the terms of the polynomials along the top and left side of a rectangle and then multiplying the terms and combining like terms.  

 

50. What is the product of 2x − 5 and 3x + 4? A  5x − 1

B  6x2 − 7x − 20

C  6x2 − 20

D  6x2 + 7x − 20

SOLUTION:  

Choice B is the correct answer.

51. Which statement is correct about the symmetry of this design?  

  F  The design is symmetrical only about the y-axis.   G  The design is symmetrical only about the x-axis.   H  The design is symmetrical about both the y- and the x-axes.   J  The design has no symmetry.

SOLUTION:  Consider each choice.   F  For the design to be symmetrical only about the y-axis, you can fold it along the y-axis. The part to the right and left of the y-axis should be identical. In this case they are. So the figure is symmetrical about the y-axis.   G  For the design to be symmetrical  about the x-axis, you can fold it on the x-axis. The part above and below the x-axis, should be identical. In this case they are not. So it is not symmetrical about the x-axis.   H  Since the figure is not symmetrical about the x-axis, you can eliminate this choice.   J  Since the figure is symmetrical about the y -axis, you can eliminate this choice.  Thus, Choice F is the correct answer.

52. Which point on the number line represents a number that, when cubed, will result in a number greater than itself? 

 

A  P   B  Q   C  R   D  T

SOLUTION:  T is the only number greater than 1, so it is the only number when cubed that will be greater than itself.   Choice D is the correct answer.

53. SHORT RESPONSE  For a science project, Jodi selected three bean plants of equal height. Then, for five days, she measured their heights in centimeters and plotted the values on the graph below.  

  She drew a line of best fit on the graph. What is the slope of the line that she drew?

SOLUTION:  The line passes through the points (1, 1) and (5, 7). 

So, the slope of the line is .

54. SAVINGS  Carrie has $6000 to invest. She puts x dollars of this money into a savings account that earns 2% interest per year. She uses the rest of the money to purchase a certificate of deposit that earns 4% interest. Write anequation for the amount of money that Carrie will have in one year.

SOLUTION:  Let x = the amount placed into the 2% interest savings account Let 6000-x = the amount placed into the 4% certificate of deposit   To calculate the amount of money that will be in the account at the end of the year, use principle (1 + rate)  time.(The 1 + the rate will add back in the original money deposited.)   Savings account:  

 

  Certificate of deposit:  

  Therefore, T = 1.02x + 1.04(6000 − x)

Find each sum or difference.

55. (7a2 − 5) + (−3a

2 + 10)

SOLUTION:  

56. (8n − 2n2) + (4n − 6n

2)

SOLUTION:  

57. (4 + n3 + 3n

2) + (2n

3 − 9n2 + 6)

SOLUTION:  

58. (−4u2 − 9 + 2u) + (6u + 14 + 2u

2)

SOLUTION:  

59. (b + 4) + (c + 3b − 2)

SOLUTION:  

60. (3a3 − 6a) − (3a

3 + 5a)

SOLUTION:  

61. (−4m3 − m + 10) − (3m

3 + 3m

2 − 7)

SOLUTION:  

62. (3a + 4ab + 3b) − (2b + 5a + 8ab)

SOLUTION:  

Simplify.

63. (−2t4)3 − 3(−2t

3)4

SOLUTION:  

64. (−3h2)3 − 2(−h

3)2

SOLUTION:  

65. 2(−5y3)2 + (−3y

3)3

SOLUTION:  

66. 3(−6n4)2 + (−2n

2)2

SOLUTION:  

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8-3 Multiplying Polynomials