Worked-out Problems

Chapter 3 continued
16. Let x the hourly wage.
Hours
Hours on Hourly Tips on
Hourly
p on p
Wednesday wage Wednesday
wage
Friday
Tips
on
Friday
5x 25 3x 30.76
5x 25 3x 3x 30.76 3x
2x 25 30.76
2x 25 25 30.76 25
2x 5.76
2 x
5. 76
2 2
x 2.88
Your friend’s hourly wage is $2.88.
17. 4x 3 2x 5
4x 3 2x 2x 5 2x
2x 3 5
2x 3 3 5 3
2x 8
2 x
8 2 2
Lesson 3.4
3.4 Checkpoint (p. 139)
1. n 7 > 3
n 7 7 > 3 7
n > 4
6 5 4 3 2 1
Check: n 7 > 3
1 7 ? > 3
6 > 3 ✓
2. 10 ≥ y 4
10 4 ≥ y 4 4
6 ≥ y, ory ≤ 6
0 2 4 6 8 10
Check: 10 ≥ y 4
10 ? ≥ 3 4
10 ≥ 7 ✓
3. 6 ≤ x 9
6 9 ≤ x 9 9
3 ≤ x, orx ≥ 3
0
12
x 4
2x 5 2(4) 5 8 5 13
P 3s 3(13) 39
The perimeter of the triangle is 39 units.
Brain Game (p. 137)
Let x the number of small boxes in each large box.
Large
boxes
Small
Small
boxes Unpacked boxes
Large
p in each small p in each
boxes
large boxes
large
box
box
3x 24 5x 10
3x 24 3x 5x 10 3x
24 2x 10
24 10 2x 10 10
14 2x
1 4
2 x
2 2
7 x
Each large box holds 7 small boxes.
3x 24 3(7) 24 21 24 45
Each person will pack 45 small boxes.
45 7 ≈ 6.4
Each person will need 7 large boxes to pack all of the
small boxes.
Unpacked
small
boxes
1
0 1 2 3 4
Check: 6 ≤ x 9
6 ? ≤ 5 9
6 ≤ 4 ✓
4. z 5 < 1
z 5 5 < 1 5
z < 6
0 2 4 6 8 10
Check: z 5 < 1
4 5 ? < 1
1 < 1 ✓
3.4 Guided Practice (p. 140)
1. Equivalent inequalities are inequalities that have the
same solution.
2. Sample answer: The graph of x > 5 has an open circle at
5 because 5 is not part of the solution. The graph of x ≥ 5
has a closed circle at 5 because 5 is part of the solution.
3. 5 < n
5 < 8, so 8 is a solution.
4. 5 < n
5 > 8, so 8 is not a solution.
12
5. 5 < n
5 < 4, so 4 is a solution.
5
90 Pre-Algebra
Chapter 3 Worked-Out Solution Key
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