Chapter 7 continued - NOHS Teachers

Chapter 7 continued
23. 3x 4y 8 Multiply by 3 →9x 12y 24
24. 6x y 12 Multiply by 2 →
Exactly one solution: 3, 6
25. y
26.
27. y
28. x ≥ 0
3
y ≥ 0
29.
31.
9
2x 6y 12 Multiply by 2 →
infinitely many solutions
4x 2y 0
1
3
y ≤ 9
5
3
x ≤ 4
y > 2x 7
x y 6
4x 4.45y 25.80
x y 6
4y 6 4.45y 25.80
4y 24 4.45y 25.80
x 4 6
x 2
1 3
1
3
0.45y 1.80
y 4
2 bags of oyster shell grit
4 bags of sunflower seeds
x
x
30.
x ≥ 0
y ≥ 0
9x 12y 24
y ≤ 2 3x 4
x ≤ 6
2
2
2
6
0 0
12x 2y 24
4x 2y 0
8x 24
x 3
63 y 12
y 6
y
6
y ≤ 2x 5
y ≥ 2x 1
x
Chapter 7 Standardized Test (pp. 444–445)
1. D
2. C
4. A
5. E
6. E
7. B
8. B
4
5 x 1 2 y 16
x y 24
4
5y 24 1 2y 16
4 5 96 5 1 2y 16
2x 7y 8
x 6y 10
26y 10 7y 8
12y 20 7y 8
3 4 x 7 10 y 5 y 12
5
1
4x 10y 3 5 Multiply by 3 →
35x 2 15x 6
x y 42
5x 2y 150
5y 42 2y 150
5y 210 2y 150
4x 2y 6
x y 24
3
10y 16 5
y 32 3
x 6y 10
5y 12
x y 42
3y 60
y 20
3. C
7x y 15 Multiply by 2 → 14x 2y 30
9. B 10. A 11. D 12. C
x y 15
x y 19
x y 15
y 15 y 19
x 17 15
2y 34
x 2
y 17
2x 7 12 5 8
2x 84 5 8
2x 44
5
22 5 12
5 2
x 22 5
3 4x 7 10y 5
3
4 x 9 10 y 15
1 5 y 10
y 50
3 4x 7 1050 5
3 4 x 35 5
x 40
x y 40 50 90
4x 2y 6
18x 36
x 2
42 2y 6
2y 2
y 1
178 Algebra 1
Chapter 7 Worked-out Solution Key
Copyright © McDougal Littell Inc.
All rights reserved.