Solving Two-Step Equations

Step 1

• Multiply out any brackets:

2(x + 3) = 20

2x + 6 = 20

Step 2

• Add or subtract to get rid of the constant:

2x + 6 = 20

2x + 6 – 6 = 20 – 6

2x = 14

Step 3

• Multiply or divide to isolate the variable:

2x = 14

2x = 14

2 2

x = 7

Example 1

3x – 6 = 15

3x – 6 + 6 = 15 + 6

3x = 21

3 3

x = 7

Example 2

+ 7 = 12

+ 7 – 7 = 12 - 7

= 5

x 2 = 5 x 2

x = 10

2

x

2

x

2

x

2

x

Example 3

-3(2x - 4) = -12

-6x + 12 = -12

-6x + 12 – 12 = -12 – 12

-6x = -24

-6 -6

x = 4

Practice

1) 2 + 4x = 2 2) -4x – 5 = -29

3) 4x + 5 = 25 4) -2x + 6 = -8

5) 1 + 2x = -1 6) -6(x + 1) = -24