Prealgebra Week 10

Equation Review

100

Solve 9x = -54

9x = -54

/9 on both sides

x = -6

200

1/5x = 5

1/5x = 5

(1/5x)*5 = (5)*5

x = 25

300

6x + 3x = 36

6x + 3x = 36

9x = 36

/9 on both sides

x = 4

400

3x + 1 = 16

3x + 1 = 16

subtract 1 from both sides

3x = 15

divide both sides by 3

x = 5

500

4x - 10 = x - 16

4x - 10 = x - 16

subtract x from both sides

3x - 10 = - 16

add 10 to both sides

3x = -6

divide both sides by 3

x = -2

Adding fractions

100

3/7 + 1/7

4/7

200

-3/7 + -4/7

-3/7 + -4/7

-7/7

-1

300

-7/9 - -3/9

-7/9 - -3/9

-7/9 + 3/9

-4/9

400

8 - 3 1/6

8 - 3 1/6

48/6 - 19/6

29/6

4 5/6

500

5 1/6 + 4 3/4 - 1 3/8

5 1/6 + 4 3/4 - 1 3/8

31/6 + 19/4 - 11/8

124/24 + 114/24-33/24

205/24

8 13/24

LCM

100

3 and 4

3, 6, 9, 12

4, 8, 12

200

3 and 6

6

300

6, 12, & 15

6:            2 * 3

12:     2 * 2 * 3

15:                  3 * 5

__________________

          2 * 2 * 3 * 5 = 60

Multiply or Divide Fractions

100

1/4 * 2/3

1/6

200

-3/8 * -4/5

3/10

300

5/21 / 15/42

2/3

400

4 2/3 / 7/15

10

500

-3 1/2 /2 4/5

-5/4 = -1 1/4