Intermediate Algebra (11th edition)

14.A chemist needs 12 L of a 40% alcohol solution. She must mix a 20% solution and a

50% solution. How many liters of each will be required to obtain what she needs?

15.A local electronics store will sell seven AC adaptors and two rechargeable flashlights for

$86, or three AC adaptors and four rechargeable flashlights for $84. What is the price of a

single AC adaptor and a single rechargeable flashlight?

16.The owner of a tea shop wants to mix three kinds of tea to make 100 oz of a mixture that

will sell for $0.83 per oz. He uses Orange Pekoe, which sells for $0.80 per oz, Irish

Breakfast, for $0.85 per oz, and Earl Grey, for $0.95 per oz. If he wants to use twice as

much Orange Pekoe as Irish Breakfast, how much of each kind of tea should he use?

Solve each system using row operations.

17.

5 x+ 5 y= 9

3 x+ 2 y= 4

CHAPTERS 1–4 Cumulative Review Exercises 261

18.

5 x+ 3 y- 5 z=- 14

3 x+ 7 y+ 4 z= 23

x+ 3 y+ 2 z= 11

Perform each operation.

Evaluate each expression if possible.

Evaluate for ,,and.

9. 
   
   
   
   10. 11.Which property of real numbers justifies the statement?
   
   
   
   

Solve each equation.

12. 
    
    
    
    13. 
        
    
    
    
    


13. for x 15.

Solve each inequality.

16. 
    
    
    
    17. 
        
    
    
    
    


17. 
    
    
    
    19. 20.A survey measured public recognition of some popular contemporary advertising
        slogans. Complete the results shown in the table if 2500 people were surveyed.
    
    
    
    

| 12 t+ 7 |Ú 0 2 x+ 375 or x- 1 ... 6

| 3 x+ 2 |... 4

2

3

x+

5

12

x... 20

ax+by=d 0.04x+0.06 1 x- 12 =1.04

712 x+ 32 - 412 x+ 12 = 21 x+ 12 | 6 x- 8 |= 4

5 + 13 # 62 = 5 + 16 # 32

| 2 x|+ 3 y-z^3 - 51 x^3 - y^32

x=- 4 y= 3 z= 6

2 0.49 - 2 0.49 2 - 0.49

1 - 324 - 34 - 1 - 324

8

15

,a-

12

5

• b

3

4

-

2

5

CUMULATIVE REVIEW EXERCISES

CHAPTERS 1–4

Source:Department of Integrated Marketing Communications, Northwestern University.

Actual Number Who

Percent Recognition Recognized Slogan

Slogan (product or company) (nearest tenth of a percent) (nearest whole number)

Please Don’t Squeeze the... (Charmin) 80.4%

The Breakfast of Champions (Wheaties) 72.5%

The King of Beers (Budweiser) 1570

Like a Good Neighbor (State Farm) 1430