3.1 Solving Literal Equations
1. x = a b
2. x = nq
3. x = r2
4. x = 3 m
5. b = y – mx
6. x = b – d
7. t = I Pr
8. c = p – a – b
9. t = d r
10. r =
2
c
π
11. s =
3
p
12. h = V2 r
π
13. P = 14
3
r x
15. x = y b m
−
16. x = ae + a
17. x1 = mx2 y1 y2 m
+ −
18. P2 = 1 1 2 1 2 PV T
TV
19. H =
2 2 2 S r r π π −
20. y = c ax b
−
21. x = – 2
b
22. y =
2
x a
−
23. n = bx x −b
24. x = r
q− Pn or
r Pn q
− −
25. v = df di t
−
; v = 88 ft/sec 26. H = 3V2
r
π ; H = 24 cm
27. h = S cr c
−
Section 3.1
28. x2 = y2 y1 mx1 m
− +
; x2 = 2 29. x = bn
n b−
30. p =
2
mr q s r
+ −
31. b =
1
c c +
32. a =
2
c x + c − d
33. T2 = 2 2 1 1 1 P V T
PV ; T2 = 171 K 34. m =
2
1 2
E
gh+ v
35–36.
Vehicle Gallons
Consumed Gallons Saved
Work van 1500
Mr. Hill
SUV 1154
346 gal
Compact
car 500
Mrs. Hill
Hybrid 250
250 gal
Old (d) m ÷ d
General
Expressions New (n)
m ÷ n
Section 3.1
37. An expression represents a single quantity, while an equation states that two different expressions are equal.
38. F = ma
39. I = R – E
40. x = 1
5
41. y = 12 42. c = 5 43. s = 42 44. a7b–4
45. c–10d 6f –3
3.2 Ratios and Proportions
1. 4 to 5 2. 4 to 3 3. 1 to 3 4. 1 to 4
5. 17 points/game 6. $2.50/gal
7. $9.25/hr 8. 25 bu/acre 9. $18.25/yr 10. 25
¢
/oz12. 27.7 m/sec 13. x = 56
14. y = 70
15. z = 1000
16. a = 36
25 = 1.44
17. b = 7
8 = 0.875
18. c = 128
7
≈ 18.3
Section 3.2
21. d = 9
22. y = 7
23. n = 9
24. p = –3
25. q = 1
2 = 0.5
26. r = 2
3 = 0.6
27. $1.33/roll
28. $1.91/roll
29. $18/shirt
30. $22.50/shirt
31. $190
32. 2.5 hr
33. 47 oz
34. 195 students
35. 18 volleyball players
36. 27 coils
37a. b s −b
37b. s b s
−
38. three-point shots
40. 7.20g/cm3
41a. 346 gal
41b. 250 gal
42. 152 gal
43. 4
9
44. –9
4
45. 25
49
46. x = –1.5 = –3
2
47. a = 135
48. x = 2n m
49. h = 2 440
11
w+
50. $2850
51. –1, 1, 3
3.3 Similar Figures and Scale Models
1. ∠R ≅ ∠Z, ∠S ≅ ∠Q, and ∠B ≅ ∠M;
RS ZQ =
SB QM =
BR MZ
2. 58°
3. x = 17.5 units; y = 20 units 4. a = 48 units; b = 54.4 units 5.
21 DEF p
= 15
6 ;
pDEF = 52.5 units
6.
42 XYZ p
= 32
10 ;
pXYZ = 134.4 units
7. 70 mi 8. 16 in.
9. 1 in. : 20 mi 10. 1 in. : 30 mi 11. 140 ft × 230 ft
12. 24 in. × 10.6 in.
13. 12 in. × 8 in.
14. 60 in. = 5 ft 15. 2.4 in.
16. 15.625 ft
18. DE = 3 units;
BC = 3.75 units 19. MNO
RTS A
A =
9
4; ARTS = 24 units 2
20
.
ABCDE FGHIJ AA =
9 16;
AABCDE = 24.75 units2
21. h = 20 units
22. s = 18 units; l = 10 units 23. S
L V
V =
8
125; VL = 3000 units 3
24. L S V
V =
27
8 ; VS = 16 units 3
25. 21.6 units and 26.4 units; 60 units
26. 6 : 5; 6 : 5 27. 4 : 25; 8 : 125 28. 3 : 2; 27 : 8 29. 147 ft2
30. 64 ft2 31. 160 ft 32. 5000 ft3
33. 1029π units3
34. 24 in.
Section 3.3
36. 48 in. by 30 in. 37. 30 in.
38. Answers will vary. 39. 4.0 units
40. 4.9 units 41a. 3
130
41b. 1
60
41c. 1
99
42. The SUV option will save the most fuel, and the new sedan option will save the least.
49. – 7
12
50. 6 5
42
51. 47
60
52. –13
3.4 The Percent Equation
1. 0.69, 69
100
2. 1.87, 187
100
3. 0.75, 3
4
4. 0.14, 7
50
5. 25%, 1
4
6. 57%, 57
100
7. 350%, 7
2
8. 0.6, 60% 9. 7.5, 750% 10. 0.125, 12.5% 11. 126
12. 24% 13. 82.76 14. 712.8 15. 3
16. 2008% 17. 33,075 18. 65
19. 500 20. 53%
21. 40%; 60% 22. 144°
23. 236 24. $1500 25. $8.57/hr 26. 69%; yes 27. 85%
28. 70 games
29. $20.6 million
30. $2.94; $51.86; no 31. 33 – 46 lb
32. 12%; Athletes 33. 167.7 lb
34. 8% protein, 22% fat, and 70% carbohydrates; too
many carbohydrates and not enough protein
Section 3.4
36. 37% protein, 32% fat, and 31% carbohydrates; too much protein and not enough carbohydrates 37. 662,080 vehicles
38. 24%
39. 9,895,000 people
40. $3.50/lb; $3.33/lb; $3.42/lb
41.–43.
Mileage of Vehicle Replacing the Following
Work Van Old Sedan Compact Car
Producing the Same Savings as the Following
NA 30.8 97.5 SUV for work van
12 25.7 NA Hybrid for compact car
44. –15 45. 5 46. 1
48
47. 0.39 48. x = 21
4 = 5.25
49. x = 28
3 = 9.3
50. x = 7.5 in. 51. 99 in.2
52. x = 4
2
bd − dpq
53. x = 3c 2b ac
3.5 Percent Change and Error
1. 25% 2. 50% 3. 650% 4. 99.75% 5. 980
6. $34 7. 270 8. 1274 9. 1230 10. 315
11. 15; 10%
12. –0.1; 4% 13. 22.2% 14. 66.7%
15. 21.1% increase; 83 16. 6.8% decrease; 550 17. 115; 17.4% increase 18. 120; 27.5% decrease
19. subtract 39; 31.2% decrease 20. add 47; 28.8% increase
23. 1400; subtract 1050 24. 19.2; add 28.8
25. 1250; 1225 26. 0.24; 0.54 27. 3.3%
28. 1.3%
29. 0.13g/mL; 13% 30. –6.0°C; 7.7%
31. 6.6% 32. 4.0% 33a. 24 33b. 16
34. No; 400% of x = 4x is the increase. The new number is x + 4x = 5x.
35. –30 (if the number
represents a quantity that can be negative; otherwise, it is not possible)
36. 125%
Section 3.5
38. The final is less than the original since the decrease is computed on a larger number than the increase. You are subtracting more than you added.
39. 20%
40. 1250 gal
41. Answers are given in terms of g, the current price per gallon.
41a. 104.17g
41b. 28.85g
41c. 20.83g
41d. 12.63g
42. x = 0.6 43. y = 7 44. z = 17
3
45. 105% 46. 6
47. 150
48. No; the sides are not proportional since 4
3
≠ 6 5.
49. 71
3
50. The Multiplication Property of Equality and the
3.6 Money
1. $4.00 2. $2.60 3. $13.00 4. $14.25 5. $4123 6. $132,050 7. 7%
8. $14,003.15 9. $12,579 10. 2.5% 11. $15; $90
12. 40%, $9.80 13. $120; $138 14. 35%; $9.11 15. $19.95; 24% 16. $23.10; $53.90 17. $6.75; 15% 18. 6%; $1800 19. $749; $501.83 20. 70%; $7.20 21. $300
23. $5000 24. 2.5%
25. $10.07; $66.00
26. J: $19.00, L: $15.50, and K: $12.75
27. $851 28. $87,500 29. 16% 30. $6630
31. $67.50; $33.75 32. $24; $45
33. $131.25; 81.25%
34. $29.90; 90%
35. $2500 at 5% and $7500 at 6%
36. $7500 at 6% and $6200 at 4%
37. $1800 for 9 mo and $2500 for 18 mo 38. $3500
39. $10,080 for 2.5 yr and $7000 for 3 yr
40. new car: $20,000; used car: $8500 41. 555
Section 3.6
42. 28 43. –6 44. 19
24
45. 197
48
46. –a2b + 2ab2
47. 2x2 – 3xy + 2y2
3.7 Motion
1. 54 2. 66 3.
19
d
4. 52t
5. 20
6. 35(r + 2) 7. r
8. 4 9. 7ab
10.
16
d
11. 125 mi 12. 6 hr
13. 400 mi/hr 14. 4 hr
15. 3
4 hr
Section 3.7
18. Frank: 12 mi/hr; Ted: 8 mi/hr
19. 6 hr
20. passenger train: 63 mi/hr; coal train: 40 mi/hr
21. up: 10 ft/sec; down: 80 ft/sec 22. 124.8 mi
23. 144 mi 24. 2 hr
25. 1 hr
26. Jay: 30r1 5 220;
r1 5 7.3 yd/sec Zeke: 30r2 5 210;
r2 5 7 yd/sec
Zeke’s time: 7t 5 220;
t < 31.4 sec 27. 8 mi by canoe;
28
–
33.Trade-in Net Cost Payback Period ROI
Work van for a used small SUV $1500 ≈ 21 mo or 1.7 yr 57.7%
Compact car for a used hybrid $5000 ≈ 96 mo or 8 yr 12.5%
Work van for a new SUV $13,000 ≈ 180 mo or 15 yr 6.7%
Compact car for a new hybrid $13,500 ≈ 259 mo or 21.6 yr 4.6%
Older sedan for a new sedan $22,500 ≈ 712 mo or 59.4 yr 1.7%
Section 3.7
34. The trade-in of the work van for a small used SUV is the most justifiable, and the work van for a new hybrid and the compact car for a used hybrid may be
reasonably justifiable based on fuel savings and ROI. Note that other costs are not being considered.
35. w = 4 36. x = –0.7 37. y = 9 38. z = 1
2
39. t = vf vi a
−
; t = 15 sec 40. 50,000
41. $25,500 42. $96
43. 52%
44. The second discount was applied only to the
3.8 Mixtures
1. 14 gal 2. 0.65x lb 3. 7.2 oz 4. 33% 5. 80 L 6. $25.20 7. $5.31n
8. 16 L 9. 0.5x
10. 0.25(x + 80)
11. 18 gal; 7.6 gal; 42% salt 12. 50 gal; 4.92 gal; 9.84% 13. 42 gal; 33% acid
14. 15%
15. 4 lb of butter scotch and 16 lb of cinnamon balls 16. 15 gal of cream
17. 21 lb of Chinese and 14 lb of Indian
Section 3.8
19. 2 gal
20. 2.4 lb of Pistachio Pleasure; 9.6 lb of Pistachio Surprise 21. 2.5 L
22. 5 gal 23. 11%
24. 18 lb of hamburger and 12 lb of sausage
25. 3 cans of grapefruit and 4 cans of pineapple
29.
30. Car B retains 38% of its value in the first 6 yr, while Car A retains only 24% of its value.
31. 24 in. 32. 21 in.2
33. 8 mi/hr 34. 11
3
35. 12 games 36. 20.5 mi/hr
New 1 yr old 2 yr old 3 yr old 4 yr old 5 yr old 6 yr old
Value $27,370 $19,506 $16,453 $10,918 $8755 $7329 $6551 Car A
Percent Change 29% 16% 34% 20% 16% 11%
Value $29,045 $22,499 $18,829 $14,509 $14,031 $12,731 $11,112 Car B
Section 3.8
37. The school exceeded its goal by 5 students
38. 0.7 g/cm3; 6.2% 39. $0
Chapter 3 Review
1. m = dv
2. x = y b m
−
3. r = S ch c
−
4. c = b a −bd
5. A =
3
SR S
+
6. v2 = a(t2 – t1) + v1;
v2 = 49 m/s
7. 275 words/page
9. 60 mi/hr 10. 27.7 m/sec 11. y = 125
3
≈ 41.6
12. x = 5
13. 10 g of hydrogen and 80 g of oxygen
14. 210 mi
15. 3 in.
16. 180 ft2
Chapter 3 Review
18. 56 cm
19. 134.4 cm2
20. 0.005, 1 200
21. 50%; 1 2 22. 0.2, 20%
23. 150
24. 475%
25. 4% increase; 936
26. subtract 50; 33.3% decrease
27. 175; 140
28. 87.5%
29. 120 people; 280 people
30. 7 PM
31. 47.7 mi/hr 32. 315 mi 33. 92.2%
34. 0.14 g/cm3; 5.2% 35. 3.6%
36. $9240; $9702 37. 38.5%
39. $15,000 40. $9200
41. $5000 at 4% and $10,000 at 6% 42. 1.5 hr
43. 5760 yd ≈ 3.3 mi
44. 3 hr
45. 30 lb of Columbian and 20 lb of Brazilian
46. 315 children and 735 adults 47. 6.6 L
Sequences—Fibonacci and Golden Ratio Sequences
1. 7, 12, 19, 31, 50 2. 9, 10, 19, 29, 48 3. –1, 2, 1, 3, 4 4. 5
2, 7 5,
12 7 ,
19 12,
31 19
5. 1, 2, 3
2, 5 3,
8 5
6. 13
8 , 21 13,
34 21,
55 34,
89 55