an explosion of math!!!! by: matt and nick. quick 1 st power equation example: 4x=12 answer: x=3
TRANSCRIPT
Special Cases of These Equations
• A. x3-7x2=-6x
-6x=-6x= (All real #’s)• B. 5x/3 + 7/2 = 4
6*5x/3 + 6*7/2 = 6*410x+21 = 2410x = 24-2110x = 3x = 3/10
• C. 4/x=12 x=3
Addition Property (of Equality)
Multiplication Property (of Equality)
Example: If x = y, then x + z = y + z.
If a+2=7, then a+2+-2=7+-2
Example: If a = b, then a * c = b * c
Reflexive Property (of Equality)
Symmetric Property (of Equality)
Transitive Property (of Equality)
Example: 3m=3m
Example:If m=n, then n=m
Example: If m=n and n=p, then m=p
Associative Property of Addition
Associative Property of Multiplication
Example:(7+1/4)+3/4=7+(1/4+3/4)
Example: a(bc) = (ab)c
Commutative Property of Addition
Commutative Property of Multiplication
Example: 1/4+7+3/4=1/4+3/4+7
Example: ab = ba
Prop of Opposites or Inverse Property of Addition
Prop of Reciprocals or Inverse Prop. of Multiplication
Example: a+(-a)=0
Example:-3/x*-x/3=1
Identity Property of Addition
Identity Property of Multiplication
Example: 0 + a = a = a + 0
Example: 1 * a = a = a * 1
Multiplicative Property of Zero
Closure Property of Addition
Closure Property of Multiplication
Example: a × 0 = 0
Example: If x and y are real numbers, then x+y is a real
number.
Example: If x and y are real numbers, then x*y is a real
number.
Product of Powers Property
Power of a Product Property
Power of a Power Property
Example: ab × ac = a(b + c)
Example: (ab)m = am · bm
Example: (ab)c = abc
Quiz Time!!!
***You will see an example problem and you will click to see the answer! There are 10 Problems so it should
only take a few minutes to complete. Have Fun!
First Power Inequalities
***In the following slides you will see how to solve first power
inequalities.
Answer: X<3
X+3<6
***To answer this, you would subtract 3 from both sides and end up isolating the variable on the left side and 3 on the other. The inequality sign would stay the same because you are not multiplying/dividing by a negative number.
Answer: -2<X<3
-2<x and x<3
***To solve a conjunction of two open sentences in a given variable, you find the values of the variable for which both sentences are true.
Answer: y<-3 or y>7
y-2<-5 or y-2>5
***To solve a disjunction of two open sentences, you find the values of the variable for which at least one of the sentences is true.
Answer: {All real Numbers}
n+5 n+5
***As you can see, the inequalities cancel out to leave a technically true statement leaving the answer to be “All real numbers”
Answer: No Solution
***Two inequalities have no solution when both of them must be true and they result in mutually exclusive conditions. Thus, there is no number that is both greater than 5 and less than 3, therefore there is no solution.
x + 5 > 10 and x -2 < 1
How To Do Linear Equations
• Slopes of All Lines:• Rising line-positive slope• Falling line-negative slope• Vertical line- undefined • Horizontal line- 0
• Equations of All Lines• Horizontal- y=c • Vertical- x=c • Diagonal- y=mx+b and Ax+By=C
Linear Equations Cont.
• Standard/general form: Ax+By=C
• Point-slope form: y-y1=m(x-x1)
• Slope intercept form: y=mx+b
• How to Graph: Video from Math TV
• Click here to Graph y=3x-1
Linear Equations Cont.
• How to Find Intercepts
1.Put the equation into Slope-Intercept form
2.Y=mx+b
3.The “b” in the equation is your Y-intercept
Substitution Method
1. Solve the first equation for y
2. Substitute this expression for y in the other equation, and solve for x.
3. Substitute the value of x in the equation in Step 1, and solve for y.
***P.417 in your book has great examples!
Elimination Method
1. Add similar terms of the two equations
2. Solve the resulting equation
3. Substitute what you got for x and plug it into either of the equations and solve for y
***P.426 in your book has great examples!
Systems of Equations
• Independent- two distinct non-parallel lines that cross at exactly one point (solution is always some x,y-point)
• Dependant- two lines that intersect at every point (solution is the whole line)
• Inconsistent- shows two distinct lines that are parallel (never intersect), has no solution
• ***Graphs of these terms are on following slide!
Graphs from www.purplemath.com
Independent system:one solution and
one intersection point
Inconsistent system:no solution and
no intersection point
Dependent system:the solution is the
whole line
Factoring
• Grouping (2x2 and 3x1)- You use this when you have 4 or more terms
• GCF- You use this when you have any number of terms
• Difference of Squares- Use this with Binomials• Sum and Difference of Cubes- Use with
Binomials• PST- Trinomials• Reverse FOIL-Trinomials
Rational Expressions
*Factor first!
Answer
Factor and Cancel
*Common factor in both the numerator and the denominator and so we can cancel the x-4 from both
Rational ExpressionsAddition and Subtraction of Rational
Expressions
*Common denominator is: 6x5
*Multiply each term by an appropriate quantity to get this in the denominator and then do the addition and subtraction
Answer
Rational ExpressionsMultiplication of Rational
Expressions
Answer
*The first thing that we should always do in the multiplication is to factor everything in sight as much as possible
*Cancel as much as we can and then do the multiplication to get the answer
Rational ExpressionsDivision of rational expressions
Answer
*Divide first!
*Once we’ve done the division we have a multiplication problem and we factor as much as possible, cancel everything that can be canceled and finally do the multiplication.
Quadratic Equations in one Variable
• Quadratic –second power
• Use the discriminant to predict how many x-intercepts each parabola will have.
Solve by FactoringSo the first thing to do is factor:
x2 + 5x + 6 = (x + 2)(x + 3)
Set this equal to zero:
(x + 2)(x + 3) = 0
Solve each factor:
x + 2 = 0 or x + 3 = 0
x = –2 or x = – 3
Answer: x2 + 5x + 6 = 0 is x = –3, –2
Method of Completing the Square
For: x2+bx+?
1. Find half the coefficient of x: b/2
2. Square the result of step 1: (b/2)2
3. Add the result of step 2 to x2+bx: x2+bx+(b/2)2
4. You have completed the square: x2+bx+(b/2)2=(x+b/2)2
Quadratic Equations in one Variable Cont.
Complete the square:
X2+14x=?
X2+14x+49= (x+7)2
(14/2)2=49
Line of Best Fit or Regression Line
• We use this to find an equation for a scatter plot.
• Your calculator will help you find the best fit line
• The calculator will find an exact regression line
Line of Best Fit or Regression Line Cont.
Write an equation of a line that has a slope of -4 and x-intercept of 3.
1. Substitute -4 for m in y=mx+b2. To find b, substitute 3 for x and 0 for y in y=-
4x+by=-4x+b0=-4(3)+b0=-12+b
12=bFinal answer: y=-4x+12
Functions
• A. f(x) means "y“ and not all functions are relations• B. A function can only use each x-value once
– Domain- set of all x-coordinates (independent)– Range- set of all y-coordinates (dependant)
• Find the range given f(x)=5x-3 and Domain={-2,0,7}. f(-2)=5(-2)-3=-13 f(0)=5(0)-3=-3 f(7)=5(7)-3=32Range={-13,-3,32}
• C. We will show hot to do a Parabola on the next slide
How to Graph a Parabola
1. The easiest way to graph a parabola is to start by finding the x-coordinate of the vertex, or the turning point of the function. Given a parabola with a general equation of y=ax²+bx+c, the x-coordinate of the vertex can be found by using x=-b/2a, which is the equation of the axis of symmetry for the parabola. The axis of symmetry runs through the vertex, and therefore shares a common point.
2. Substitute the x value of the vertex back into the function to find the y value of the vertex.
3. After you've found your turning point, you can select two x-values to the right of the turning point and two values to the left of the turning point.
4. Plot all points
Simplifying Expressions with Exponents
1. x6 × x5 = (x6)(x5) = (xxxxxx)(xxxxx) (6 times, and then 5 times) = xxxxxxxxxxx (11 times) = x11
2. Simplify (–46x2y3z)0 This is simple enough: anything to the zero power is just 1.
(–46x2y3z) =1
3.
The "minus" on the 2 says to move the variable; the "minus" on the 6 says that the 6 is negative. Warning: These two "minus" signs mean entirely different things, and should not be confused. I have to move the variable; I should not move the 6.
*** The answer is -6x2
2
6
x
Simplifying Expressions with Radicals
1. Simplify
2. Simplify
3. Simplify
54
54 9 6 3 6
3 3203 3 3320 64 5 4 5
4 2a b4 2 2a b a b
Word Problems
1. Problem: The sum of twice a number plus 13 is 75. Find the number.
Hint: The word is means equals. The word and means plus. Therefore, you can rewrite the problem like the following:
The sum of twice a number and 13 equals 75.
Solution: 2N + 13 = 75
N=31
Word Problems Cont.
2. At the same moment, two trains leave Chicago and New York. They move towards each other with constant speeds. The train from Chicago is moving at speed of 40 miles per hour, and the train from New York is moving at speed of 60 miles per hour. The distance between Chicago and New York is 1000 miles. How long after their departure will they meet?
x/40 = (1000-x)/60, we can simplify it as x/40 + x/60 = 1000/60, or
x = 40 * 1000/(40 + 60) = 400
*The time that it takes the train from Chicago to travel 400 miles, is x divided by the speed of the Chicago train, which is t = x / 40 = 10.
***So, the answer is: 10 hours.
Word Problems Cont.
3. The total receipts for a hockey game are $1400 for 788 tickets sold. Adults paid $2.50 for admission and students paid $1.25. How many of each kind of tickets were sold?
• Alright, let's denote the quantity of ADULT tickets sold as x. Since the total number of tickets is The quantity of student tickets was 788, the number of student tickets is 788-x. What we need to do now is write the total $$ figure for the revenue. Since every adult ticket fetched 2.50, adults collectively have paid x*2.50. The students paid 1.25, and since we had 788-x of them, they paid the sum of (788-x)*1.25. So, we have total revenue = x*2.50 + (788-x)*1.25
• What we know is that the total revenue for the basketball game was 1400. This gives us the equation
• 1400 = x*2.50 + (788-x)*1.25
• Rewriting, we get
• x*(2.50-1.25) = 1400 - 788*1.25 or x*1.25 = 415 or x = 415/1.25 or x = 332
• That's the number of adult tickets. The number of student tickets is, therefore, 788-x, or 456. That's it!
***The answer is 332 adult tickets and 456 student tickets!
Word Problems Cont.
• Alright. So, we have 4(x-4) = 3x-4 or 4x - 4*4 = 3x-4 or, moving everything x-related to the left and numbers to the right, 4x - 3x = 4*4 - 4 x(4 - 3) = 4*4 - 4 or, dividing by 4 - 3: x = (4*4 - 4) / ( 4 - 3 ) or, calculating x, x = 12
***Bob's age is 12. His father is 36 years old.