Practice
Direct and Inverse Variation

Directions: Solve. Assume that y varies directly as x. [Remember that a direct variation is described by an equaion of the form y = kx where k≠0.]

1. If y = −4 when x = 2, find y when x = −6.

 

3. If y = −5 when x = 12.5, find x when y = 15.

 

5. If y = 80 when x = 32, find x when y = 100.

 

7. If y = 28 when x = 168, find y when y = 108.

 

2. If y = 16 when x = 4. find y when x = 6.

 

4. If y = 7 when x = 4, find y when x = 12.

 

6. If y = 198 when x = 22, find y when x = 182.

 

8. If y = 24 when x = 6, find y when x = −4.

 

Directions: Solve. Assume that y varies inversely as x. [Remember that an inverse variation is described by an equaion of the form xy = k where k≠0.]

9. If y = −4 when x= 2, find y when x = −6.

 

11. If y = −5 when x = 12.5, find x when y = 15.

 

13. If y =27 when x = 12, find x when y = −12.

 

15. If y = 60 when x = 80, find x when y = −20.

 

10. If y = 16 when x = 4, find y when x = 6.

 

12. If y = 7 when x = 4, find y when x = 12.

 

14. If y = 6 when x = −4, find x when y = 12/5.

 

16. If y = 40 when x = 16, find y when x = 10.