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Intermediate Algebra

Chapter 3

Intermediate AlgebraChapter 3
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3.3

yes, yes yes, yes

3.4

no, no yes, yes

3.9





3.10





3.13

x-intercept: (2,0),(2,0),
y-intercept: (0,−2)(0,−2)

3.14

x-intercept: (3,0),(3,0),
y-intercept: (0,2)(0,2)

3.15

x-intercept: (4,0),(4,0),
y-intercept: (0,12)(0,12)

3.16

x-intercept: (8,0),(8,0),
y-intercept: (0,2)(0,2)

3.23

4 3 4 3

3.24

3 5 3 5

3.25

undefined

3.26

0

3.27

−1 −1

3.28

10

3.31

m=25;(0,−1)m=25;(0,−1)
m=14;(0,2)m=14;(0,2)

3.32

m=43;(0,1)m=43;(0,1)
m=32;(0,6)m=32;(0,6)

3.35

intercepts horizontal line slope-intercept vertical line

3.36

vertical line slope-intercept horizontal line
intercepts

3.37

50 inches
66 inches
The slope, 2, means that the height, h, increases by 2 inches when the shoe size, s, increases by 1. The h-intercept means that when the shoe size is 0, the height is 50 inches.

3.38

40 degrees
65 degrees
The slope, 14,14, means that the temperature Fahrenheit (F) increases 1 degree when the number of chirps, n, increases by 4. The T-intercept means that when the number of chirps is 0, the temperature is 40°.

3.39

$25
$85
The slope, 4, means that the weekly cost, C, increases by $4 when the number of pizzas sold, p, increases by 1. The C-intercept means that when the number of pizzas sold is 0, the weekly cost is $25.

3.40

$35
$170
The slope, 1.8,1.8, means that the weekly cost, C, increases by $1.80$1.80 when the number of invitations, n, increases by 1.
The C-intercept means that when the number of invitations is 0, the weekly cost is $35.

3.41

parallel not parallel; same line

3.42

parallel not parallel; same line

3.43

parallel parallel

3.44

parallel parallel

3.45

perpendicular not perpendicular

3.46

perpendicular not perpendicular

3.47

y = 2 5 x + 4 y = 2 5 x + 4

3.48

y = x 3 y = x 3

3.49

y = 3 5 x + 1 y = 3 5 x + 1

3.50

y = 4 3 x 5 y = 4 3 x 5

3.51

y = 2 5 x 1 y = 2 5 x 1

3.52

y = 3 4 x 4 y = 3 4 x 4

3.53

y = 8 y = 8

3.54

y = 4 y = 4

3.55

y = 1 3 x 10 3 y = 1 3 x 10 3

3.56

y = 2 5 x 23 5 y = 2 5 x 23 5

3.57

x = 5 x = 5

3.58

x = −4 x = −4

3.59

y = 3 x 10 y = 3 x 10

3.60

y = 1 2 x + 1 y = 1 2 x + 1

3.61

y = 1 3 x + 10 3 y = 1 3 x + 10 3

3.62

y = −2 x + 16 y = −2 x + 16

3.63

y = −5 y = −5

3.64

y = −1 y = −1

3.65

x = −5 x = −5

3.66

x = −4 x = −4

3.67

yes yes yes yes no

3.68

yes yes no no
yes

3.69

y −2 x + 3 y −2 x + 3

3.70

y 1 2 x 4 y 1 2 x 4

3.71

x 4 y 8 x 4 y 8

3.72

3 x y 6 3 x y 6

3.73



All points in the shaded region and on the boundary line, represent the solutions to y>52x4.y>52x4.

3.74



All points in the shaded region, but not those on the boundary line, represent the solutions to y<23x5.y<23x5.

3.75



All points in the shaded region, but not those on the boundary line, represent the solutions to 2x3y<6.2x3y<6.

3.76



All points in the shaded region, but not those on the boundary line, represent the solutions to 2xy>3.2xy>3.

3.77



All points in the shaded region, but not those on the boundary line, represent the solutions to y>3x.y>3x.

3.78



All points in the shaded region and on the boundary line, represent the solutions to y−2x.y−2x.

3.79



All points in the shaded region, but not those on the boundary line, represent the solutions to y<5.y<5.

3.80



All points in the shaded region and on the boundary line represent the solutions to y−1.y−1.

3.81

10x+13y26010x+13y260


Answers will vary.

3.82

10x+17.5y28010x+17.5y280


Answers will vary.

3.83

{1,2,3,4,5}{1,2,3,4,5}
{1,8,27,64,125}{1,8,27,64,125}

3.84

{1,2,3,4,5}{1,2,3,4,5}
{3,6,9,12,15}{3,6,9,12,15}

3.85

(Khanh Nguyen, kn68413), (Abigail Brown, ab56781), (Sumantha Mishal, sm32479), (Jose Hern and ez, jh47983) {Khanh Nguyen, Abigail Brown, Sumantha Mishal, Jose Hern and ez} {kn68413, ab56781, sm32479, jh47983}

3.86

(Maria, November 6), (Arm and o, January 18), (Cynthia, December 8), (Kelly, March 15), (Rachel, November 6) {Maria, Arm and o, Cynthia, Kelly, Rachel} {November 6, January 18, December 8, March 15}

3.87

(−3,3),(−2,2),(−1,0),(−3,3),(−2,2),(−1,0),
(0,−1),(2,−2),(4,−4)(0,−1),(2,−2),(4,−4)
{−3,−2,−1,0,2,4}{−3,−2,−1,0,2,4}
{3,2,0,−1,−2,−4}{3,2,0,−1,−2,−4}

3.88

(−3,0),(−3,5),(−3,−6),(−3,0),(−3,5),(−3,−6),
(−1,−2),(1,2),(4,−4)(−1,−2),(1,2),(4,−4)
{−3,−1,1,4}{−3,−1,1,4}
{−6,0,5,−2,2,−4}{−6,0,5,−2,2,−4}

3.89

Yes; {−3,−2,−1,0,1,2,3};{−3,−2,−1,0,1,2,3};
{−6,−4,−2,0,2,4,6}{−6,−4,−2,0,2,4,6}
No; {0,2,4,8};{0,2,4,8};
{−4,−2,−1,0,1,2,4}{−4,−2,−1,0,1,2,4}

3.90

No; {0,1,8,27};{0,1,8,27};
{−3,−2,−1,0,2,2,3}{−3,−2,−1,0,2,2,3}
Yes; {7,−5,8,0,−6,−2,−1};{7,−5,8,0,−6,−2,−1};
{−3,−4,0,4,2,3}{−3,−4,0,4,2,3}

3.91

no {NBC, HGTV, HBO} {Ellen Degeneres Show, Law and Order, Tonight Show, Property Brothers, House Hunters, Love it or List it, Game of Thrones, True Detective, Sesame Street}

3.92

No {Neal, Krystal, Kelvin, George, Christa, Mike} {123-567-4839 work, 231-378-5941 cell, 743-469-9731 cell, 567-534-2970 work, 684-369-7231 cell, 798-367-8541 cell, 639-847-6971 cell}

3.93

yes no yes

3.94

no yes yes

3.95

f(3)=22f(3)=22 f(−1)=6f(−1)=6 f(t)=3t22t1f(t)=3t22t1

3.96

(2)=13(2)=13 f(−3)=3f(−3)=3
f(h)=2h2+4h3f(h)=2h2+4h3

3.97

4m274m27 4x194x19
x12x12

3.98

2k2+12k2+1 2x+32x+3
2x+42x+4

3.99

t IND; N DEP 205; the number of unread emails in Bryan’s account on the seventh day.

3.100

t IND; N DEP 460; the number of unread emails in Anthony’s account on the fourteenth day

3.101

yes no

3.102

no yes

3.115

The domain is [−5,1].[−5,1]. The range is [−4,2].[−4,2].

3.116

The domain is [−2,4].[−2,4]. The range is [−5,3].[−5,3].

3.117

f(0)=0f(0)=0 f=(π2)=2f=(π2)=2 f=(−3π2)=2f=(−3π2)=2 f(x)=0f(x)=0 for x=−2π,π,0,π,2πx=−2π,π,0,π,2π (−2π,0),(π,0),(0,0),(π,0),(2π,0)(−2π,0),(π,0),(0,0),(π,0),(2π,0) (0,0)(0,0) [−2π,2π][−2π,2π] [−2,2][−2,2]

3.118

f(0)=1f(0)=1 f(π)=−1f(π)=−1 f(π)=−1f(π)=−1 f(x)=0f(x)=0 for x=3π2,π2,π2,3π2x=3π2,π2,π2,3π2 (−2pi,0),(−pi,0),(0,0),(pi,0),(2pi,0)(−2pi,0),(−pi,0),(0,0),(pi,0),(2pi,0) (0,1)(0,1) [−2pi,2pi][−2pi,2pi] [−1,1][−1,1]

Section 3.1 Exercises

1.
3.
5.

A: yes, B: no, C: yes, D: yes A: yes, B: no, C: yes, D: yes

7.

A: yes, B: yes, C: yes, D: no A: yes, B: yes, C: yes, D: no

9.
11.
13.
15.
17.
19.
21.
23.
25.





27.





29.
31.
33.

( 3 , 0 ) , ( 0 , 3 ) ( 3 , 0 ) , ( 0 , 3 )

35.

( 5 , 0 ) , ( 0 , −5 ) ( 5 , 0 ) , ( 0 , −5 )

37.

( 5 , 0 ) , ( 0 , −5 ) ( 5 , 0 ) , ( 0 , −5 )

39.

( 2 , 0 ) , ( 0 , 6 ) ( 2 , 0 ) , ( 0 , 6 )

41.

( 2 , 0 ) , ( 0 , −8 ) ( 2 , 0 ) , ( 0 , −8 )

43.

( 5 , 0 ) , ( 0 , 2 ) ( 5 , 0 ) , ( 0 , 2 )

45.
47.
49.
51.
53.
55.
57.
59.
61.
63.
65.
67.
69.

Answers will vary.

71.

Answers will vary.

Section 3.2 Exercises

73.

2 5 2 5

75.

5 4 5 4

77.

1 3 1 3

79.

5 2 5 2

81.

0

83.

undefined

85.

5 2 5 2

87.

8 7 8 7

89.

7 3 7 3

91.

−1 −1

93.
95.
97.
99.
101.

m = −7 ; ( 0 , 3 ) m = −7 ; ( 0 , 3 )

103.

m = −3 ; ( 0 , 5 ) m = −3 ; ( 0 , 5 )

105.

m = 3 2 ; ( 0 , 3 ) m = 3 2 ; ( 0 , 3 )

107.

m = 5 2 ; ( 0 , −3 ) m = 5 2 ; ( 0 , −3 )

109.
111.
113.
115.
117.

vertical line

119.

slope-intercept

121.

intercepts

123.

intercepts

125.

$31
$52
The slope, 1.75,1.75, means that the payment, P, increases by $1.75$1.75 when the number of units of water used, w, increases by 1. The P-intercept means that when the number units of water Tuyet used is 0, the payment is $31.

127.

$42
$168.50
The slope, 0.575 means that the amount he is reimbursed, R, increases by $0.575 when the number of miles driven, m, increases by 1. The R-intercept means that when the number miles driven is 0, the amount reimbursed is $42.

129.

$400
$940
The slope, 0.15,0.15, means that Cherie’s salary, S, increases by $0.15 for every $1 increase in her sales. The S-intercept means that when her sales are $0, her salary is $400.

131.

$1570
$5690
The slope gives the cost per guest. The slope, 28, means that the cost, C, increases by $28 when the number of guests increases by 1. The C-intercept means that if the number of guests was 0, the cost would be $450.

133.

parallel

135.

neither

137.

parallel

139.

perpendicular

141.

neither

143.

perpendicular

145.

perpendicular

147.

neither

149.

parallel

151.

Answers will vary.

153.

Answers will vary.

Section 3.3 Exercises

155.

y = 3 x + 5 y = 3 x + 5

157.

y = −3 x 1 y = −3 x 1

159.

y = 1 5 x 5 y = 1 5 x 5

161.

y = −1 y = −1

163.

y = 3 x 5 y = 3 x 5

165.

y = 1 2 x 3 y = 1 2 x 3

167.

y = 4 3 x + 3 y = 4 3 x + 3

169.

y = −2 y = −2

171.

y = 5 8 x 2 y = 5 8 x 2

173.

y = 3 5 x + 1 y = 3 5 x + 1

175.

y = 3 2 x + 9 y = 3 2 x + 9

177.

y = −7 x 10 y = −7 x 10

179.

y = 5 y = 5

181.

y = −7 y = −7

183.

y = x + 8 y = x + 8

185.

y = 1 4 x 13 4 y = 1 4 x 13 4

187.

y = 2 x + 5 y = 2 x + 5

189.

y = 7 2 x + 4 y = 7 2 x + 4

191.

x = 7 x = 7

193.

y = −4 y = −4

195.

y = 4 x 2 y = 4 x 2

197.

y = 2 x 6 y = 2 x 6

199.

x = −3 x = −3

201.

y = −2 y = −2

203.

y = 1 2 x + 1 y = 1 2 x + 1

205.

y = 4 3 x y = 4 3 x

207.

y = 3 2 x + 5 y = 3 2 x + 5

209.

y = 5 2 x y = 5 2 x

211.

y = 4 y = 4

213.

y = −4 y = −4

215.

x = −2 x = −2

217.

y = 4 y = 4

219.

y = 1 2 x + 5 y = 1 2 x + 5

221.

y = 1 6 x y = 1 6 x

223.

y = 4 3 x 3 y = 4 3 x 3

225.

y = 3 4 x + 1 y = 3 4 x + 1

227.

x = −2 x = −2

229.

x = −2 x = −2

231.

y = 1 5 x 23 5 y = 1 5 x 23 5

233.

y = −2 x 2 y = −2 x 2

235.

Answers will vary.

Section 3.4 Exercises

237.

yes yes no no no

239.

no no yes yes no

241.

yes no no no no

243.

y 3 x 4 y 3 x 4

245.

y 1 2 x + 1 y 1 2 x + 1

247.

x + y 5 x + y 5

249.

3 x y 6 3 x y 6

251.
253.
255.
257.
259.
261.
263.
265.
267.
269.
271.
273.
275.
277.

11x+16.5y33011x+16.5y330


Answers will vary.

279.

15x+10y50015x+10y500


Answers will vary.

281.

Answers will vary.

Section 3.5 Exercises

283.

{1, 2, 3, 4, 5} {4, 8, 12, 16, 20}

285.

{1, 5, 7, −2} {7, 3, 9, −3, 8}

287.

(Rebecca, January 18), (Jennifer, April 1), (John, January 18), (Hector, June 23), (Luis, February 15), (Ebony, April 7), (Raphael, November 6), (Meredith, August 19), (Karen, August 19), (Joseph, July 30)
{Rebecca, Jennifer, John, Hector, Luis, Ebony, Raphael, Meredith, Karen, Joseph}
{January 18, April 1, June 23, February 15, April 7, November 6, August 19, July 30}

289.

(+100, 17. 2), (110, 18.9), (120, 20.6), (130, 22.3), (140, 24.0), (150, 25.7), (160, 27.5) {+100, 110, 120, 130, 140, 150, 160,} {17.2, 18.9, 20.6, 22.3, 24.0, 25.7, 27.5}

291.

(2, 3), (4, −3), (−2, −1), (−3, 4), (4, −1), (0, −3) {−3, −2, 0, 2, 4}
{−3, −1, 3, 4}

293.

(1, 4), (1, −4), (−1, 4), (−1, −4), (0, 3), (0, −3) {−1, 0, 1} {−4, −3, 3,4}

295.

yes {−3, −2, −1, 0, 1, 2, 3} {9, 4, 1, 0}

297.

yes {−3, −2, −1, 0, 1, 2, 3} 0, 1, 8, 27}

299.

yes {−3, −2, −1, 0, 1, 2, 3} {0, 1, 2, 3}

301.

no {Jenny, R and y, Dennis, Emily, Raul} {RHern and ez@state.edu, JKim@gmail.com, Raul@gmail.com, ESmith@state.edu, DBroen@aol.com, jenny@aol.cvom, R and y@gmail.com}

303.

yes yes no

305.

yes no yes

307.

f(2)=7f(2)=7 f(−1)=−8f(−1)=−8 f(a)=5a3f(a)=5a3

309.

f(2)=−6f(2)=−6 f(−1)=6f(−1)=6 f(a)=−4a+2f(a)=−4a+2

311.

f(2)=5f(2)=5 f(−1)=5f(−1)=5
f(a)=a2a+3f(a)=a2a+3

313.

f(2)=9f(2)=9 f(−1)=6f(−1)=6
f(a)=2a2a+3f(a)=2a2a+3

315.

g(h2)=2h2+1g(h2)=2h2+1
g(x+2)=2x+5g(x+2)=2x+5
g(x)+g(2)=2x+6g(x)+g(2)=2x+6

317.

g(h2)=−3h22g(h2)=−3h22
g(x+2)=−3x8g(x+2)=−3x8
g(x)+g(2)=−3x10g(x)+g(2)=−3x10

319.

g(h2)=3h2g(h2)=3h2
g(x+2)=1xg(x+2)=1x
g(x)+g(2)=4xg(x)+g(2)=4x

321.

2

323.

6

325.

22

327.

4

329.

t IND; N DEP
N(4)=165N(4)=165 the number of unwatched shows in Sylvia’s DVR at the fourth week.

331.

x IND; C DEP
N(0)=1500N(0)=1500 the daily cost if no books are printed
N(1000)=4750N(1000)=4750 the daily cost of printing 1000 books

Section 3.6 Exercises

337.

no yes

339.

no yes

341.




D:(-∞,∞), R:(-∞,∞)

343.




D:(-∞,∞), R:(-∞,∞)

345.




D:(-∞,∞), R:(-∞,∞)

347.




D:(-∞,∞), R:(-∞,∞)

349.




D:(-∞,∞), R:{5}

351.




D:(-∞,∞), R: {−3}{−3}

353.




D:(-∞,∞), R:(-∞,∞)

355.




D:(-∞,∞), R:(-∞,∞)

357.




D:(-∞,∞), R:[0,∞)

359.




(-∞,∞), R:(-∞,0]

361.




(-∞,∞), R:[-∞,0)

363.




(-∞,∞), R:[−1,−1, ∞)

365.




D:(-∞,∞), R:(-∞,∞)

367.




D:(-∞,∞), R:(-∞,∞)

369.




D:[0,∞), R:[0,∞)

371.




D:[1,∞), R:[0,∞)

373.




D:[ −1,−1, ∞), R:[−∞,∞)

375.




D:(-∞,∞), R:[1,∞)

377.

D: [2,∞), R: [0,∞)

379.

D: (-∞,∞), R: [4,∞)

381.

D: [−2,2],[−2,2], R: [0, 2]

383.

f(0)=0f(0)=0 (pi/2)=−1(pi/2)=−1
f(−3pi/2)=−1f(−3pi/2)=−1 f(x)=0f(x)=0 for x=−2pi,pi,0,pi,2pix=−2pi,pi,0,pi,2pi
(−2pi,0),(pi,0),(−2pi,0),(pi,0), (0,0),(pi,0),(2pi,0)(0,0),(pi,0),(2pi,0) (f)(0,0)(f)(0,0)
[−2pi,2pi][−2pi,2pi] [−1,1][−1,1]

385.

f(0)=−6f(0)=−6 f(−3)=3f(−3)=3 f(3)=3f(3)=3 f(x)=0f(x)=0 for no x none y=6y=6 [−3,3][−3,3]
[−3,6][−3,6]

Review Exercises

391.
393.

,

395.
397.
399.
401.
403.
405.
407.

( 0 , 3 ) ( 3 , 0 ) ( 0 , 3 ) ( 3 , 0 )

409.

( 6 , 0 ) , ( 0 , 3 ) ( 6 , 0 ) , ( 0 , 3 )

411.

( 16 , 0 ) , ( 0 , −12 ) ( 16 , 0 ) , ( 0 , −12 )

413.
415.
417.
419.

1

421.

1 2 1 2

423.

undefined

425.

0

427.

−6 −6

429.

5 2 5 2

431.
433.
435.

m = 5 3 ; ( 0 , −6 ) m = 5 3 ; ( 0 , −6 )

437.

m = 4 5 ; ( 0 , 8 5 ) m = 4 5 ; ( 0 , 8 5 )

439.
441.
443.

horizontal line

445.

intercepts

447.

plotting points

449.

$250$250
$450
The slope, 35, means that Marjorie’s weekly profit, P, increases by $35 for each additional student lesson she teaches.
The P-intercept means that when the number of lessons is 0, Marjorie loses $250.

451.

neither

453.

not parallel

455.

y = −5 x 3 y = −5 x 3

457.

y = −2 x y = −2 x

459.

y = −3 x + 5 y = −3 x + 5

461.

y = −4 y = −4

463.

y = 3 5 x y = 3 5 x

465.

y = −2 x 5 y = −2 x 5

467.

y = 1 2 x 5 2 y = 1 2 x 5 2

469.

y = 2 y = 2

471.

y = 2 5 x + 8 y = 2 5 x + 8

473.

y = 3 y = 3

475.

y = 3 2 x 6 y = 3 2 x 6

477.

y = 1 y = 1

479.

yes no yes yes; no

481.

y > 2 3 x 3 y > 2 3 x 3

483.

x 2 y 6 x 2 y 6

485.
487.
489.
491.

20x+15y60020x+15y600



Answers will vary.

493.

D: {−3, −2, −1, 0}
R: {7, 3, 9, −3, 8}

495.

(4, 3), (−2, −3), (−2, −1), (−3, 1), (0, −1), (0, 4),
D: {−3, −2, 0, 4}
R: {−3, −1, 1, 3, 4}

497.

yes {−3, −2, −1, 0, 1, 2, 3}
{0, 1, 8, 27}

499.

{−3, −2, −1, 0, 1, 2, 3}
{−3, −2, −1, 0, 1, 2, 3}
{−243, −32, −1, 0, 1, 32, 243}

501.

yes

503.

yes

505.

f(−2)=−10f(−2)=−10 f(3)=5f(3)=5 f(a)=3a4f(a)=3a4

507.

f(−2)=20f(−2)=20 f(3)=0f(3)=0 f(a)=a25a+6f(a)=a25a+6

509.

2

511.

18

513.

yes

515.

no

517.

yes

519.

no

521.




D: (-∞,∞), R: (-∞,∞)

523.




D: (-∞,∞), R: (-∞,∞)

525.




D: (-∞,∞), R: (-∞,0]

527.




D: (-∞,∞), R: (-∞,∞)

529.




D: [−2,−2, ∞), R: [0,∞)

531.




D: (-∞,∞), R: [1,∞)

533.

D: (-∞,∞), R: [2,∞)

535.

f(x)=0f(x)=0 f(π/2)=1f(π/2)=1
f(−3π/2)=1f(−3π/2)=1 f(x)=0f(x)=0 for x=−2π,π,0,π,2πx=−2π,π,0,π,2π
(−2π,0),(−2π,0), (π,0),(π,0), (0,0),(0,0), (π,0),(π,0), (2π,0)(2π,0) (f)(0,0)(f)(0,0)
[−2π,2π][−2π,2π] [−1,1][−1,1]

Practice Test

537.
539.

3535 undefined

541.
543.
545.
547.

y = 2 x + 5 y = 2 x + 5

549.

y = 4 5 x 5 y = 4 5 x 5

551.
553.
555.

yes {−3,−2,−1,0,1,2,3}{−3,−2,−1,0,1,2,3} {0, 1, 8, 27}

557.

12

559.




D: (-∞,∞), R: [1,∞)

561.

x=−2,2x=−2,2 y=−4y=−4
f(−1)=−3f(−1)=−3 f(1)=−3f(1)=−3
D: (-∞,∞) R: [−4,−4, ∞)

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