Worked-out Problems

Chapter 3 continued
54. 3x 5 2x
3x 5 3x 2x 3x
5 x
5 x
1
1
5 x
2x 2(5) 10
P 4s 4(10) 40
The perimeter of the square is 40 units.
55. x 12 > 96
x 12 12 > 96 12
x > 84
56. x 17 ≥ 44
x 17 17 ≥ 44 17
x ≥ 27
57. x 26 ≤ 33
x 26 26 ≤ 33 26
x ≤ 59
58. x 14 < 29
x 14 14 < 29 14
x < 43
3.5 Standardized Test Practice (p. 148)
t
x
59. D; ≥ 3 60. I; < 6
9
7
25
? ≥ 3
14
? < 6
9
7
2.7 ≥/ 3 2 < 6
61. C; 18 ≤ 3p
18 3p
≤
3 3
6 ≤ p, orp ≥ 6
Brain Game (p. 148)
Erika e
Dawn d
Matthew m
1. e 4
82 83 84 85 86 87 88
0 9 18 27 36 45 54
55 56 57 58 59 60 61
39 40 41 42 43 44 45
2. c > 4d, c > 4(3), c > 12
3. e > a, d > a, s > a
Charlie c
Anthony a
Stephanie s
4. e ≤ 13, c ≤ 13, d ≤ 13, a ≤ 13, m ≤ 13, s ≤ 13
98 Pre-Algebra
Chapter 3 Worked-Out Solution Key
5. m > 3 cousins
6. s 6 e 6 4 10
7. e ≥ 2, c ≥ 2, d ≥ 2, a ≥ 2, m ≥ 2, s ≥ 2
8. e d 1
4 d 1
4 1 d 1 1
3 d
9. Either c 6, a 6, or m 6.
From the information given you know that Erika is
4 years old, Stephanie is 10 years old, and Dawn is
3 years old. You are given that Charlie’s age is greater
than 12, but less than or equal to 13. So, Charlie must be
13 years old. Dawn is older than Anthony, but Anthony
must be greater than or equal to 2 years old. So, Anthony
must be 2 years old. One boy must be 6 years old.
Because Charlie is 13 years old and Anthony is 2 years
old, Matthew must be 6 years old.
In order from least to greatest age, the cousins are:
Anthony: 2 y, Dawn: 3 y, Erika: 4 y, Matthew: 6 y,
Stephanie: 10 y, and Charlie: 13 y.
Lesson 3.6
3.6 Checkpoint (p. 149)
1. Let g the average number of goals per game.
Goals Number Goals
School
scored this of games p scored >
record
season left per game
52 12g > 124
52 12g 52 > 124 52
12g > 72
1 2g
> 7 2
12
12
g > 6
Your team must score, on average, more than 6 goals
per game.
3.6 Guided Practice (p. 151)
1. 5 2x < 20
5 2x 5 < 20 5
2x < 15
2 x
< 1 5
2 2
x < 7.5
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