3-6 Clearing Fractions

9P6: Write and Use equivalent forms of equations

To clear fractions

• Find LCM

• Multiply it to all terms

• Don’t forget the integer terms!!!

Understand6 + 5 =116(2) + 5 = 11(2) If multiply by one term are both sides still equal?

No!

What would we have to do to make left equal to right now?

Multiply 5 by 2 also!!!

6(2) + 5(2) =11(2)

*****You have to multiply (or divide) all terms in an equation by the same factor!!!!*****

Review for finding LCM

4

3

6

1

9

2

Find factors of each number

9: 3*3 6: 2*3 4: 2*2

The only factors needed to make all denominators is 2 and 3

LCM (Most)

Which one needs most 2: 4

Which one needs most 3: 9 so LCM is 2*2*3*3 or 36

Examples: #1

32

1

4

3

8

7 xx What is the LCM(D)?

All denominators are factors of 2

8 needs the most so 8 is LCM

Multiply all terms by 8

Then complete as before

7x + 6 = 4x + 24

-4x -4x

3x + 6= 24

-6 -6

3x = 18

3 3

x = 6

#2

33

12

4

1 xx

What is LCM?

Do they share any common factors?

No

So LCM is 4*3 =123x + 24 = 4x – 36

-3x -3x

24 = x - 36

+36 +36

60 = x

#35)

4

1

3

2(2

6

1 x Distribute

What is LCM?

6:2*3

3:3

2:2 so LCM is 6

52

1

3

4

6

1 x

-1 - 8x + 3 = -30 CLT

-8x + 2 = -30

-2 -2

-8x = -32

-8 -8

x = 4

Clearing Decimals

• Multiply by the place value of the smallest place

• Ex: 0.06 (multiply by 100)

• Ex: 0.8 (multiply by 10)

• Ex: 0.809 (multiply by 1000)

#4

0.5 x + 3 = 0.85x – 5 50 x + 300 = 85 x - 500

-50x -50x

300 = 35x -500

+500 +500

800 = 35x

15 35

800 = x or 160

35 7

We need to multiply by 100 to move all decimals 2 places!!

Marker Board pg140

• 6

• 12

• 18

• 22

Assignment

3-6/140-141/ 1-23o, 33-39o