Practice Makes Perfect Algebra - Carolyn Wheater [43]
7. 6x2 + 29x − 5
8. 5 − l3b − 6b2
9. 6x2 + x − 35
10. −10x2 + 29x − 10
11. x2 − 16
12. x2 − 9
13. 4x2 − 1
14. 9x2 − 25
15. 49 − 9x2
16.(x + 3)(x + 2) = x2 + 5x + 6
17.(x − 7)(x − 2) = x2 − 9x + 14
18.(2a + 1)(a + 4) = 2a2 + 9a + 4
19.(3x − 2)(x − 5) = 3x2 − 17x + 10
20.(2t + 3)(3t − 5) = 6t2 − t − 15
6.8
1. 2a3 + 19a2 + 38a + 21
2. 6b3 + 13b2 + 16b + 15
3. 4c3 − 39c2 + 54c + 16
4. 8x4 − 18x3 + 17x2 − 19x + 7
5. y3 − y2 − 19y + 4
6. x3 − 6x2 + 12x − 8
7. t3 − 8
8. x3 + 1
9. x4 + 4x3 − 16x − 16
10. 2y4 − y3 − 8y2 + 34y − 15
6.9
1. 8c3d2
2. 5d4
3. 4x7
4. 5y4
5. −4x2 y
6. 1
7. −3t2
8. −18r2
9. 8x − 9x4
10. 5y3 − 7y5
11. x + 3
12. 9 − 13y
13. 8z8 − 7z7 + 6z6 − 5z5
14. 3x3y2 − 9x2y3 + 27xy4
15. 3x2 − x + 4
6.10
1. x − 7
2. y + 4
3. 2x + 3
4. 7x2 + 5
7. 2b − 1
9. x2 + 6
10. 4y2 − 2y + 1
7 Factoring
7.1
1. y(y − 15)
2. 3b(b − 2)
3. 8ab(4a + 5)
4. 5(y2 + 3y + 4)
5. x3y4(x5 − xy3 + y)
6. −a2(1 + a − 2a2)
7. 25x4(1 − 2x + 5x3)
8. 8r(r + 3t + 2)
9. 16x2 y(y − 3x)
10. 3xy(x + 2 + 5xy)
7.2
1.(x + 5)(x + 7)
2.(x + 4)(x + 7)
3.(x − 3)(x − 5)
4.(x − 3)(x − 4)
5.(x + 5)(x − 4)
6.(x − 3)(x + 1)
7.(x − 9)(x − 2)
8.(x − 11)(x + 2)
9.(x + 13)(x − 3)
10.(x + 4)(x + 8)
7.3
1.(3x + 5)(x + 2)
2.(2x − 1)(x − 1)
3.(2x + 1)(x + 3)
4.(6x + 1)(2x + 5)
5.(2x + 3)(3x + 4)
6.(10x + 1)(x − 5)
7.(3x − 5)(3x − 4)
8.(3x + 2)(6x + 1)
9.(3x + 1)(5x − 6)
10.(x − 6)(4x − 5)
7.4
1.(x + 7)(x − 7)
2.(x + 3)2
3.(6t + 1)(6t − 1)
4.(3t − 4)2
5.(4 + y)(4 − y)
6.(3y + 7)2
7.(2x + 9)(2x − 9)
8.(2x + 1)2
9.(4a + 3y)(4a − 3y)
10.(x − 6)2
8 Radicals
8.1
8.2
8.3
8.4
1. x = 9
2. No solution
3. x = 81
4. No solution
5. y = 50
6. No solution
7. x = 17
8. x = 26
9. x = 11
8.5
1. x = 5
2. x = 5
3. x = 4
4. x = −125
5. x = 3
7. x = 9
8. x = 25
9. x = −1.75
10. x = 11
8.6
9 Quadratic equations and their graphs
9.1
9.2
9.3
11. b2 − 4ac = 61, two irrational solutions
12. b2 − 4ac = −11, no real solutions
13. b2 − 4ac = 25, two rational solutions
14. b2 − 4ac = 0, one rational solution
15. b2 − 4ac = 24, two irrational solutions
16. b2 − 4ac = 1, two rational solutions
17. b2 − 4ac = 44, two irrational solutions
18. b2 − 4ac = −31, no real solutions
19. b2 − 4ac = 0, one rational solution
20. b2 − 4ac = 69, two irrational solutions
9.4
1. x = −2, x = −3
2. x = 4, x = 3
3. y = 2, y = −4
4. a = 5, a = −2
5. x = 4, x = −5
6. x = 5, x = 1
7. x = 0, x = −3
8. x = 0, x = 5
9.5
1.(3, 0),(1, 0),(0, 3)
2.(5, 0),(−1, 0),(0, −5)
3.(−2, 0),(0, 0)
4.(3, 0),(4, 0),(0, 12)
6. x = 4,(4, −1)
7. x = −2,(−2, −6)
8. x = 1,(1, 1)
9. x = 3,(3, 2)
10. x = 2,(2, 11)
9.6
10 Proportion and variation
10.1
1. 45°, 60°, 75°
2. 8 ft. and 12 ft.
3. 104 and 39
4. 20 oz
5. 24, 32, and 64
6. 20 and 24
7. 6 and 14
8. 51
9. 8 and 20
10. 6 and 20
10.2
1. x = 4.2
2. w = 15
3. x = 25
5. x = 15
6. x = 29
7. x = ±8
8. x = ±5
9. x = ±13
10. x = 7, x = −4
10.3
1. 42
2. 100
3. 312
4. 1275
5. 700
6. 0.009 V
7. 143 mi
8. 0.6 mi
9. 304 cm3
10. 70 mi
10.4
1. y = 3
2. x = 16
3. y = 8
4. t = 44
5. a = 12
6. 4 cm
7. 14.4 psi
8. 5.5 h
9. Approximately 2.8 × 1012 N
10. 3 ft
10.5
1. y = 180
2. x = 8
3. z = 7
4. y = 5
5. x = 21
6. z = 42
7. 20 cm
8. Approximately 683 N
9. Approximately 7.8 ft3
11 Rational equations and their graphs
11.1
11.2
11.3
11.4
11.5
11.6
11.7
6. y = −5
7. x = 3
8. x = 8
9. x = −9
10. x = 4
11.8
11.9
2. 2.4 min
3. 9 h
6. 3 mon
7. 2.1 days
9. 18 h
12 Exponential growth and decay
12.1
1. $5304.50
2. $14802.44
3. $2977.73
4. $3052.24
5. $327,148.96
6. $6204.59
7. $8492.03
8. $5977.69
9. $30,491.91
10. $59,913.95
12.2
1. Growth
2. Decay
3. Decay
4. Growth
5. Decay
6. Growth, 3,355,443,200 bacteria
7. Decay, 102.4 mg
8. Growth, approximately 379,518
9. Decay, $16,355.33
10. Decay, 36,652.78 acres
12.3
13 Matrix algebra
13.1
1. 2 × 4
2. 1 × 4
3. 3 × 2
4. 2 × 1
5. 3 × 3
6. b(1, 3)