2. Main Idea and New Vocabulary
Key Concept: Subtraction Property of Equality
Example 1: Solve Addition Equations
Example 2: Real-World Example
Key Concept: Addition Property of Equality
Example 3: Solve a Subtraction Equation
Example 4: Real-World Example: Solve a Subtraction Equation
Five-Minute Check
Lesson Menu

3. Solve addition and subtraction equations.
equivalent equation
Main Idea/Vocabulary

4. Key Concept

5. Solve Addition Equations
Solve 14 + y = 20. Check your solution.
14 + y = 20 Write the equation.
– 14 = – 14 Subtraction Property of Equality
y = 6 Simplify.
Answer: The solution is 6.
Check
14 + y = 20 Write the original equation.
= 20 Replace y with 6. ?
20 = 20 The sentence is true. 
Example 1

6. Solve 6 + x = 16. Check your solution.
A. 9
B. 10
C. 21
D. 22
Example 1 CYP

7. FRUIT A grapefruit weighs 11 ounces, which is 6 ounces more than an apple. How much does the apple weigh?
Example 2

8. – 6 = – 6 Subtraction Property of Equality
11 = a + 6 Write the equation.
 – 6 = – 6 Subtraction Property of Equality
5 = a Simplify.
Answer: The apple weighs 5 ounces.
Example 2

9. SHOPPING A pair of sunglasses costs $25
SHOPPING A pair of sunglasses costs $25. A book costs $10 less than the pair of sunglasses. How much is the book?
A. $35
B. $34
C. $25
D. $15
Example 2 CYP

10. Key Concept

11. Solve a Subtraction Equation
Solve 12 = z – 8. Check your solution.
12 = z – 8 Write the equation.
 + 8 = + 8 Addition Property of Equality
20 = z Simplify.
Answer: The solution is 20.
Check
12 = z – 8 Write the original equation. ?
 12 = 20 – 8 Replace z with 20.
12 = 12 Simplify. 
Example 3

12. Solve 17 = y – 4. Check your solution.
A. 21
B. –21
C. 13
D. –13
Example 3 CYP

13. Solve a Subtraction Equation
MUSIC Vivian practiced the piano for 32 minutes. She practiced 11 minutes less than her brother did. How long did her brother practice the piano?
Example 4

14. Solve a Subtraction Equation
32 = b – 11 Write the equation.
 + 11 = + 11 Addition Property of Equality
43 = b Simplify.
Answer: Vivian’s brother practiced piano for 43 minutes.
Example 4

15. HEIGHT Seth is 68 inches tall, which is 4 inches shorter than Abraham
HEIGHT Seth is 68 inches tall, which is 4 inches shorter than Abraham. How tall is Abraham?
A. 72 inches
B. 71 inches
C. 64 inches
D. 63 inches
Example 4 CYP

16. Solve x + 31 = 53. Check your solution.
A. 84
B. 83
C. 22
D. 21
Five Minute Check 1

17. Solve –5 + y = 13. Check your solution.
A. 8
B. 9
C. 18
D. 19
Five Minute Check 2

18. Solve r – 7.2 = 22.8. Check your solution.
A. 14.6
B. 15.6
C. 29
D. 30
Five Minute Check 3

19. Solve –11 = 8 + a. Check your solution.
B. 3
C. –19
D. 19
Five Minute Check 4

20. The sum of a number and 8 is –13. Find the number.
C. –21
D. 21
Five Minute Check 5

21. Write and solve an equation to determine Dale’s top speed at the racetrack if Dale’s top speed was 17 mph less than Andy’s.
A. s – 17 = 152; s = 169 mph
B. s – 17 = 152; s = 168 mph
C s = 152; s = 135 mph
D s = 152; s = 134 mph
Five Minute Check 6

22. The combined ages of the students in a 7th grade class is 1,582
The combined ages of the students in a 7th grade class is 1,582. The combined ages of the students in the 8th grade class is 34 more than the combined ages of the students in the 7th grade class. Which equation can help you find the combined ages of the students in the 8th grade class?
A. h = 1,582 – 34
B. 1,582 – h = 34
C. 1, = h
D. 34 = h + 1,582
Five Minute Check 7