7th Grade Math

= Step-by-Step Solutions begin on page R1.

Extra Practice begins on page EP2.

Examples 1–3 Evaluate each expression. Justify each step.

10. (1 + 8) × 3 11. 10 - (3 + 4) 12. (25 ÷ 5) + 8
    1313 (11 - 2) ÷ 9 14. 3 · 2 + 14 ÷ 7 15. 4 ÷ 2 - 1 + 7


11. 12 + 6 ÷ 3 - 4 17. 18 - 3 · 6 + 5 18. 6 × 10 2


12. 3 × 10 4 20. 5 × 4 3 + 2 21. 8 × 7 2 - 6


13. 8 ÷ 2 × 6 + 6 2 23. 9 2 - 14 ÷ 7 · 3


14. (17 + 3) ÷ (4 + 1) 25. (6 + 5) · (8 - 6)


15. 6 + 2(4 - 1) + 4 × 9 27. 3(4 + 7) - 5 · 4 ÷ 2

Example 4 Write an expression for each situation. Then evaluate it.

28. MP3 PLAYERS The table shows what Reina Reina’s Purchases

Item Quantity CostUnit

MP3 player 1 $200

pack of

batteries 3$4

songs 6 $2

bought at an electronics store. What is the

total cost of her purchases?

29. BOOKS Used paperback books are $0.25,
    and hardback books are $0.50. If you buy
    3 paperback books and 5 hardback books,
    how much money do you spend?

Evaluate each expression. Justify each step.

30. (2 + 10)^2 ÷ 4 31. ( 3^3 + 8) - (10 - 6)^2


31. 3 · 4(5.2 + 3.8) + 2.7 33. 7 × 9 - (4 - 3.2) + 1.8


32. MONEY Suppose you order 2 pizzas, 2 garlic Item Cost
    14” pizza $8
    garlic bread $2
    BBQ wings $4

breads, and 1 order of BBQ wings. Write an

expression to find the amount of change you

would receive from $30. Then evaluate the

expression.

3535 GRAPHIC NOVEL Refer to the graphic novel frame below. Write and

evaluate an expression to find the cost of 275 text messages.

B

Lesson 1B Expressions 31

Caitlyn is helping

Dario figure out

what his text

messaging bill will

be this month.

025-041_C1_L1_895130.indd 31 12/29/09 12:25 PM