Solve an equation using subtractionEXAMPLE 1

Solve x + 7 = 4.

x + 7 = 4 Write original equation.

x + 7 – 7 = 4 – 7 Use subtraction property of equality: Subtract 7 from each side.

x = –3 Simplify.

ANSWERThe solution is –3.

Solve an equation using subtraction

EXAMPLE 1

CHECK Substitute –3 for x in the original equation.

x + 7 = 4 Write original equation.

–3 + 7 = 4? Substitute –3 for x.

4 = 4 Simplify. Solution checks.

Solve an equation using addition

EXAMPLE 2

Solve x – 12 = 3.

Horizontal format Vertical format

x – 12 = 3 Write original equation. x – 12 = 3

Add 12 to each side. + 12 + 12

x = 15 Simplify. x = 15

x – 12 + 12 = 3 + 12

Solve an equation using division

EXAMPLE 3

Solve –6x = 48.

–6x = 48

x = –8

Write original equation.

–6x–6

48–6= Divide each side by –6.

Simplify.

GUIDED PRACTICE for Examples 1, 2, and 3

1. y + 7 = 10

ANSWER 3

Solve the equation. Check your solution.

2. x – 5 = 3

GUIDED PRACTICE for Examples 1, 2, and 3

8ANSWER

Solve the equation. Check your solution.

GUIDED PRACTICE

3. q – 11 = –5

for Examples 1, 2, and 3

6ANSWER

Solve the equation. Check your solution.

GUIDED PRACTICE

4. 6 = t – 2

for Examples 1, 2, and 3

8ANSWER

Solve the equation. Check your solution.

GUIDED PRACTICE

5. 4x = 48

for Examples 1, 2, and 3

12ANSWER

Solve the equation. Check your solution.

GUIDED PRACTICE

6. –65 = –5y

for Examples 1, 2, and 3

13ANSWER

Solve the equation. Check your solution.

GUIDED PRACTICE

7. 6w = –54

for Examples 1, 2, and 3

–9ANSWER

Solve the equation. Check your solution.

GUIDED PRACTICE

8. 24 = –8n

for Examples 1, 2, and 3

–3ANSWER

Solve the equation. Check your solution.