Intermediate Algebra (11th edition)

31. (a) (b) (c) (d)


32. (a) (b) (c) (d)


33. (a) (b) 37. (a)

(b) 39. (a) (b)

41. (a) (b) 43. (a)

(b) 45. 47. 49. 51.

53. 
    
    
    
    55. (a) (b)
    
    
    
    


54. (a) (b) 59. (a) (b)


55. (a) (b)not possible 63. (a) (b)


56. (a) (b) 67. (a)
    (b) 69. (a) (b)


57. (a) (b) 73. (a) (b)


58. ; , , 77.

79.

81. (a) (b) 5, 574.50 ; The cost for 5 tickets

and a parking pass is $574.50. (c)$237 83. (a)
(b) ; The cost for a 5-month membership is $304. (c)$591

85. (a) (b) The cost of the plan for 5 months
    is $336. (c)$756 87. (a) (b) ; It costs $60

to rent the saw for 5 days. (c)18 days 89. (a) ;
Sales of digital cameras in the United States increased by

$1294.7 million per yr from 2003 to 2006. (b)$9099.8 million

91. (a) (b)$48.5 billion; It is greater than the

actual value. 93.32; 212 94. and 95.

96. 
    
    
    
    97. 98.86° 99.10°
    
    
    
    


97. 
    
    
    
    101. 
         
         
         
         103. 
              
         
         
         
         
    
    
    
    

Summary Exercises on Slopes and Equations

of Lines (page 174)

1. 
   
   
   
   2. 
      
      
      
      3. 2 4. 5.undefined 6. 0 7. (a)
         (b) 8. (a) (b)
      
      
      
      
   
   
   
   


2. (a) (b) 10. (a) (b)


3. (a) (b) 12. (a)

(b) 13. (a) (b)

14. (a) (b) 15. (a)

(b) 16. (a) (b)

17. (a) (b) 18. (a)B (b)D (c)A

(d)C (e)E

Connections (page 179) We include a calculator graph and supporting

explanation only with the answer to Problem 1.

1. (a) 5 - 0.6 6 ; The graph of y 1 = 5 x+ 3 has x-intercept 1 - 0.6, 0 2.

y=- 7 x+ 3 7 x+y= 3

5 x+ 2 y= 4 y=^23 x+ 8 2 x- 3 y=- 24

y= 2 x- 10 2 x-y= 10 y=- 25 x+ 2

3 x+y= 10 y= 32 x+^1432 x- 3 y=- 14

y=- 97 9 y=- 7 y=- 3 x+ 10

y=- 25 x 5 x+ 2 y= 0 y=- 8 y=- 8

5 x+ 6 y= 26 y= 3 x+ 11 3 x-y=- 11

-^35 - 74 52 y=- 65 x+^133

• 40° 1 - q, 2 2 A-q,- 34 D

F= 59 C+ 32 C= 951 F- 322

9

1 0, 32 2 1 100, 212 (^25)
y=5.25x+22.25
y=1294.7x+ 3921
y= 6 x+ 30 1 5, 60 2
y= 60 x+ 36 1 5, 336 2 ;
1 5, 304 2
y= 41 x+ 99
y=112.50x+ 12 1 2
1 5, 15.50 2 , 1 10, 31.00 2 y= 111 x; 1 0, 0 2 , 1 5, 555 2 , 1 10, 1110 2
y= 45 x 1 0, 0 21 5, 225 21 10, 450 2 y=3.10x; 1 0, 0 2 ,
y=- 21 x+ 9 x+ 2 y= 18 y= 7 y= 7
3 x-y= 19 y=^12 x- 1 x- 2 y= 2
2 x- 13 y=- 6 y= 132 x+ 136 y= 3 x- 19
x= 7 y=- 3 y=- 3
x+ 2 y= 8 y=-^12 x+ 4 y= 5 y= 5
x=0.5 2 x-y= 2 y= 2 x- 2
y=1.4x+ 4 y= 5 x= 9 y=- 23 y= 8
4 x-y= 12 y= 4 x- 12 7 x- 5 y=- 20
y=- 43 x+ 25 x- 2 y=- 13 y= 21 x+^132
2 x+y= 18 y=- 2 x+ 18 3 x+ 4 y= 10
x
y
0
(0, –2) (2, –3)
x + 2y = –4
y=- 21 x- 2 -^121 0,- 22
x
y
0
(5, 0)
(0, – 4)
4 x – 5y = 20
y= 54 x- 4 45 1 0,- 42 (b) ; The graph of lies
abovethex-axis for values of
x greater than
(c) ; The graph of lies
belowthex-axis for values of
x less than

2. (a) (b) (c) 3. (a)
   (b) (c) 4. (a) (b)
   (c)

Section 3.4 (pages 179 –181)

1.solid; below 3.dashed; above 5.The graph of

divides the plane into two regions. In one of the regions, the ordered

pairs satisfy. In the other, they satisfy.

7. 
   
   
   
   9. 
      
      
      
      11. 
          
      
      
      
      
   
   
   
   


8. 
   
   
   
   15. 
       
       
       
       17. 
           
       
       
       
       
   
   
   
   


9. 
   
   
   
   21. 
       
       
       
       23. 
           
       
       
       
       
   
   
   
   


10. 
    
    
    
    27. 
        
    
    
    
    

x

y

0

x + y > –5

andy < –2

x

y

0

2 x – y≥ 2

andy < 4

x + y≤ 1

and

x≥ 1

0

y

x

y<x

2

(^20)
y
x x
y
0
1
3
x – 3y≤ 0
x
y
0
–4
4
x + y > 0
–5
x
y
0
3
5 x – 3y > 15
(^2) x
y
0 3
2 x + 3y≥ 6
x
y
0
–2
x + 3y≥ –2
x – (^23)
y
01
–4
4 x – y < 4
x
y
0
(^22)
x + y≤ 2
Ax+By 6 C Ax+By 7 C
Ax+By=C
3 - 3,q 2
1 - q,-1.2 4 3 - 1.2,q 2 5 - 36 1 - q,- 34
5 - 0.5 6 1 - 0.5,q 2 1 - q,-0.5 2 5 - 1.2 6

• 0.6.

1 - q,-0.6 2 y 1

• 0.6.

1 - 0.6,q 2 y 1

Answers to Selected Exercises A-7

10

–10

–10 10

y 1 = 5x + 3

29.

x

y

–3 0

–3

3

3

⏐x⏐< 3

• 36 x 63

31.

x

y

0

–5

5

–3 1

⏐x+ 1⏐ < 2

• 26 x+ 162 33.

x

y

0

x – y≥ 1

ory≥ 2

35.

x

y

0

x – 2 > y

orx < 1

37.

x

y

0

3 x + 2y < 6

or

x – 2y > 2

39.C 41.A 43. (a) (b)

(c) 45. (a) (b)

(c) 47.

yÚ 3000

1 - q, 3.5 2 x...200,xÚ100,

1 - 4,q 2 5 3.5 6 1 3.5,q 2

5 - 46 1 - q,- 42

48. y

x

0 200 400

1000

3000

5000

49. 50.Some examples are
    and
    The corner points are and
    51.The least value occurs when
    x= 100 andy=3000.

1 200, 3000 2.

1 100, 3000 2

1 100, 5000 2 , 1 150, 3000 2 , 1 150, 5000 2.

C= 50 x+ 100 y