Intermediate Algebra (11th edition)

35. 390 37. 395 39.31,375 41.$465 43.$2100 per month

45.68; 1100 47.no; 3; 9 49. 18 51.

Section 12.3 (pages 698–700)

1. 3.not geometric 5. 7.
   There are alternative forms of the answers in Exercises 9–13.


2. 
   
   
   
   11. 
       
       
       
       13. 
           
       
       
       
       
   
   
   
   


3. 
   
   
   
   17. , or 19.
   
   
   
   

21.2, 6, 18, 54, 162 23.5, , , 25. 27.

29.2.662 31. 33.$33,410.84 35.$104,273.05 37. 9

39. 
    
    
    
    41. 43.The sum does not exist. 45. ft
    
    
    
    

47.3 days; g 49. (a) billion units

(b)approximately 12 yr 51.

53. 
    
    
    
    54. 
        
        
        
        55. 
            
        
        
        
        
    
    
    
    


54. Therefore,

57.B 58.

59.

61. 
    

Section 12.4 (page 705)

1. 720 3.40,320 5. 15 7. 1 9. 120 11. 15 13. 78


2. 
   
   
   
   17. 
       
   
   
   18. 
       
   
   
   
   


3. 
   
   
   
   23. 
       
   
   
   
   


4. 
   
   
   
   27. 
       
   
   
   
   

29.

31. 
    
    
    
    33. 
        
    
    
    
    


32. 
    
    
    
    37. 
        
        
        
        39. 
            
            
            
            41. 
                
            
            
            
            
        
        
        
        
    
    
    
    

Chapter 12 Review Exercises (pages 709–710)

1. 1, 3, 5 2.0, , , 3.1, 4, 9, 16 4. , , ,
   5.0, 3, 8, 15 6.1, 3, 7.


2. 
   
   
   
   9. 
      
      
      
      10. 18
      
      
      
      
   
   
   
   


3. 126 12. 13.$15,444 billion 14.arithmetic;

15.arithmetic; 16.geometric; 17.geometric;
18.neither 19.geometric; 20. 89 21. 73 22. 69

23. 
    
    
    
    24. 
        
        
        
        25. 15 26. 22 27. 152
        
        
        
        
    
    
    
    


24. 164 29. 30.


25. 
    
    
    
    32. or
    
    
    
    


26. 
    
    
    
    34. 0 35. 1 36.The sum does not exist.
    
    
    
    


27. 32 p^5 - 80 p^4 q+ 80 p^3 q^2 - 40 p^2 q^3 + 10 pq^4 - q^5

341

1024

21 - 3210 =118,098 51229 = 2560 51 - 229 =- 2560

an=

2

3

a

1

5

b

n- 1

an=- 1142 n^1

an=- 5 n+ 1 an=- 3 n+ 9

r=^12

d= 4 r=-^12 r=- 1

(^2827840) d= 3
2 + 3 + 4 + 5 + 6 + 7 11 + 16 + 21 + 26

• 2, - 4 1 + 4 + 9 + 16 + 25

1

16

1

8

1

4

1

2

3

4

2

3

1

• 1, 2

36 k^7160 x^6 y^34320 x^9 y^4

7 x^2 y^6

16

t^20 + 10 t^18 u^2 + 45 t^16 u^4 + 120 t^14 u^61201272 m^7 n^3

1760 r^9 s^3314 x^14 - 1413132 x^13 y+ 9113122 x^12 y^2 - 36413112 x^11 y^3

27 x^6 - 27 x^4 y^2 + 9 x^2 y^4 - y^6 r^12 + 24 r^11 s+ 264 r^10 s^2 +

x^8 + 4 x^6 + 6 x^4 + 4 x^2 + 1

x^4

16

• 
  

x^3 y

2

+

3 x^2 y^2

2

• 2 xy^3 +y^4

10 a^2 b^3 + 5 ab^4 - b^58 x^3 + 36 x^2 + 54 x+ 27

m^4 + 4 m^3 n+ 6 m^2 n^2 + 4 mn^3 +n^4 a^5 - 5 a^4 b+ 10 a^3 b^2 -

a^3 - 3 a^2 b+ 3 ab^2 - b^3

104 + 101 112 = 105 = 21 9 x^2 +^12 xy+^4 y^2

4

10 +

1

0.49999Á= 0.4+0.09999Á= 10 1 0.9999Á 2 =

0.99999Á= 1

a 1

1 - r

=

0.9

1 - 0.1

=

0.9

0.9

=1;

0.33333Á 0.66666Á 0.99999Á

$50,000a

3

4

b

8

L$5005.65

(^14) 1.1 1 1.06 25 L1.5
10 a
3
5
b
4
10,000 11 - 209 L1.3

• 2.982
  
  
  • 1, 51 - 251 1251 243121 - 1.997
  
  
  
  

2 a

1

2

b

24

=

1

223

1

354,294

1

2

a

1

3

b

11

21529 =3,906,250

an= 10 a-

1

5

b

n- 1

an=- 2 a-

1

3

b

n- 1

an=- 5122 n-^1

r= 2 r=- 3 r=-^12

1

2

38.

39. 
    
    
    
    40. 
        
    
    
    
    


40. ; 42. ;


41. ; 44. ;


42. 
    
    
    
    46. 
        
        
        
        47. 
            
        
        
        
        
    
    
    
    


43. 49.10 sec 50.$21,973.00

51.approximately 42,000 52. 53. (a)

(b) (c)

54.No, the sum cannot be found, because. This value of

rdoes not satisfy.

Chapter 12 Test (page 711)

[12.1]1.0, 2, 0, 2, 0 [12.2]2.4, 6, 8, 10, 12 [12.3]3.48, 24, 12, 6,

3 [12.2]4. 0 [12.3]5. or [12.2]6. 75

[12.3]7.124 or 44 [12.1]8.85,311 [12.3]9.$137,925.91

10.It has a sum if. [12.2]11. 70 12. 33 13.125,250

[12.3]14. 42 15. 16.The sum does not exist. [12.4]17.40,320

18. 1 19. 15 20. 66 21.


19. [12.1]23.$324 [12.3]24.

Chapters 1–12 Cumulative Review Exercises

(pages 712–713)

[1.2, 1.3]1. 8 2. [1.1]3. , 10, 0, 0.82,

4. , [2.1]5. [2.5]6. [2.7]7.
   [2.1]8. [2.6]9.
   [2.7]10. [3.2]11. [3.3]12.
   [3.1]13. [3.4]14.

[3.5]15. (a)yes (b) (c)

[4.1, 4.4]16. [4.2, 4.4]17.

[4.3]18.2 lb [5.4]19. 20.

[5.2]21. [5.5]22.

[6.2]23. [6.3]24.

25. [6.5]26. [9.7]27.

[5.1]28. 29. [7.1]30. [7.2]31.

[7.4]32. [9.2]33. [8.4]34.

[8.7]35. 73 [10.1]36.

1

9

x-

5

9

ƒ -^11 x 2 =

x- 5

9

, or ƒ -^11 x 2 =

e 1022

• 5  2217
  12
  0 f

3 p- 26

p 1 p+ 321 p- 42

x+ 7

x- 2

• 
  

27 p^2

10

9

4

1 c+ 3 d 21 c^2 - 3 cd+ 9 d^22 E-^52 , 2F 3 - 2, 3 4

z 13 z+ 4212 z- 12 17 a^2 + 3 b 217 a^2 - 3 b 2

3

3 t- 2

• 5 m^3 - 3 m^2 + 3 m+ 8 2 t^3 + 3 t^2 - 4 t+ 2 +

20 p^2 - 2 p- 6 9 k^2 - 42 k+ 49

51 - 1, - 226 51 2, 1, 4 26

5 - 3, -2, 0, 1, 2 6 5 2, 6, 4 6

4 x – y < 4

–4

01

y

x – 3y = 6 x

–2

0

y

x

1 - q, - 34 ́ 3 8, q 2 43 3 x+y= 4

596 1 - q, - 32 ́ 1 4, q 2

213 - (^23) E^16 F 3 10, q (^2) E- 29 , 6F

• 55 - 38 45151 or 32 , - 3

2013112 =3,542,940

14,080x^8 y^4

9

81 k^4 - 540 k^3 + 1350 k^2 - 1500 k+ 625

1

3

|r| 61

(^643) - (^643)
|r| 61
r= 2
5
9
1
10
5
10
a
1
10
b
2

• 5
  10
  a
  1
  10
  b
  3
  +Á
  5
  10
  +^5
  10
  a^1
  10
  1281 b+
  an= 27 a^1
  3
  b
  n- 1
  an= 2142 n-^1 an= 5 n- 3 an=- 3 n+ 15
  a 15 = 38 S 10 = 95 a 9 = 6561 S 10 =-14,762
  a 10 = 1536 S 10 = 1023 a 40 = 235 S 10 = 280
  81 t^12 - 108 t^9 s^2 + 54 t^6 s^4 - 12 t^3 s^6 +s^8775213216 a^16 b^3
  x^8 + 12 x^6 y+ 54 x^4 y^2 + 108 x^2 y^3 + 81 y^4

Answers to Selected Exercises A-31