R2 Selected Answers and SolutionsSelected Answers and Solutions
55 _mn 4 =^
2(6)
_ 4 Replace m with 2 and n with 6.= 12 _ 4 Multiply.
= 3 Divide.- 17 11. 17 13. 2 15. 3 17. 96 19. 71 21. $17
2323 The total cost is equal to the $50 fee plus $0.17
times m, number of miles.
50 + 0.17m = 50 + 0.17(150) Replace m with 150.
= 50 + 25.50 Multiply.
= 75.50 Divide.
The cost is $75.50. - 9.1 27. 37.85 29. Sample answer: 5x - 37 if
x= 8 31. Sample answer: The fee to rent a bicycle
is $10 plus $5 for each hour. The expression 5x + 10
represents the total cost for renting a bicycle for x
hours. 33. A 35. 4(8) + 3(5); $47
Pages 40–41 Lesson 1-1D- 7(4) + 7(3); 49 3. 3(9 + 6); 45
55 4(12 + 5); $68; Sample answer: The expression
12 + 5 represents the cost of one ticket and one hot
dog. The expression 4(12 + 5) represents the cost
of four tickets and four hot dogs. Since 4 × 12 = 48
and 4 × 5 = 20, find 48 + 20, or 68, to fi nd the total
cost of four tickets and four hot dogs. - Sample answer: Rewrite 44 + (23 + 16) as
44 + (16 + 23) using the Commutative Property of
Addition. Rewrite 44 + (16 + 23) as (44 + 16) + 23
using the Associative Property of Addition. Find
44 + 16, or 60, mentally. Then fi nd 60 + 23, or 83,
mentally. 9. 2(6) + 2(7); 26 11. 4(3 + 8); 44 - Sample answer: Rewrite (8 + 27) + 52 as
(27 + 8) + 52 using the Commutative Property of
Addition. Rewrite (27 + 8) + 52 as 27 + (8 + 52)
using the Associative Property of Addition. Find
8 + 52, or 60, mentally. Then fi nd 60 + 27, or 87,
mentally. 15. Sample answer: Rewrite 91 +
(15 + 9) as 91 + (9 + 15) using the Commutative
Property of Addition. Rewrite 91 + (9 + 15) as
(91 + 9) + 15 using the Associative Property of
Addition. Find 91 + 9, or 100, mentally. Then fi nd
100 + 15, or 115, mentally. 17. Sample answer:
Rewrite (4 · 18) · 25 as (18 · 4) · 25 using the
Commutative Property of Multiplication. Rewrite
(18 · 4) · 25 as 18 · (4 · 25) using the Associative
Property of Multiplication. Find 4 · 25, or 100,
mentally. Then fi nd 100 · 18, or 1,800, mentally.
1919 Sample answer: Rewrite 15 · (8 · 2) as
15 · (2 · 8) using the Commutative Property of
Multiplication. Rewrite 15 · (2 · 8) as (15 · 2) · 8
using the Associative Property of Multiplication.
Find 15 · 2, or 30, mentally. Then find 30 · 8, or 240,
mentally. - Sample answer: Rewrite 5 · (30 · 12) as 5 ·
(12 · 30) using the Commutative Property of
Multiplication. Rewrite 5 · (12 · 30) as (5 · 12) · 30
using the Associative Property of Multiplication.
Find 5 · 12, or 60, mentally. Then fi nd 60 · 30, or
1,800, mentally. 23. 5(20 + 7); 135 million- 7(9 - 3); 42 27. 9(7 - 3); 36 29. y + 5 31. 32 b
- 2 x + 6 35. 6 c + 6 37. Sample answer: 6 × 0 = 0
- false; (11 + 18) × 5 = 145; 11 + 18 × 5 = 101
- Sample answer: Using properties with real
numbers helps to understand mathematical
relationships. 43. G
Pages 42–43 Lesson 1-2A- 486 posts 3. 19 h 5. 24,900 mi 7. 6 tins
99 Find how many passengers are in one run. So,
multiply 8 by 4. Then divide the number of
passengers that can ride in one hour by the number
of passengers that can ride in one run.
1,056 ÷ 32 = 33. So, 33 runs. - 5:10 p.m.
Pages 46–49 Lesson 1-2B- 9 is added to each term; 36, 45, 54 3. 0.1 is
added to each term; 1.4, 1.5, 1.6
55 First, fi nd how many inches the plant’s height
increases each month. Look at the pattern in the
table.
Month 123
Height (in.) 369
+ 3 + 3
The plant’s height increases by 3 inches each
month. Let n represent the number of months. So,
3 n represents the total height after n months.
3 n Write the expression.
3(12) Replace n with 12.
36 Multiply.
So, the plant’s height is 36 inches.- 6 is added to each term; 25, 31, 37 9. 12 is added
to each term; 67, 79, 91 11. 5 is added to each
term; 53, 58, 63 13. 0.8 is added to each term; 5.6,
6.4, 7.2 15. 1.5 is added to each term; 10.5, 12.0,
13.5 17. 4 is added to each term; 20.6, 24.6, 28.6 - 7 n; 42 laps
2121 25 is added to each term; 95 +^25 = 120;
120 + 25 = 145; 145 + 25 = 170. So, the next three
terms are 120, 145, and 170. - 12, 7, 2 25. 8.5, 8, 7.5 27a. Sample answer: For
each text message over 250, the cost increases by
$0.15. 27b. 0.15n + 5 27c. $8.75; $12.50; $16.25 - 1,400 31. 20 33. 7,425
3535 a. Each fi gure is 8 less than the previous fi gure.
b. In fi gure 3, there are 48 rectangles. 48 - 8 = 40;
40 - 8 = 32. So, in the next two fi gures there will
be 40 and 32 rectangles.
- 2, + 4, + 6, + 8, ... ; 30, 42, 56 39. Sample
R01_R42_EM_SelAns_895130.indd R2 1/18/10 9:50 AM