Question

Reason Abstractly Ify varies directly with x, write an equation for the direct variation. Then find each value. 10. Find y when x = 15 if y = 6 when x = 30. 9. Hy= 14 when x = 8. find y when x= 12. 12. Find x when y = 14, ify = 7 when x= 8. 11. If y = 6 when x= 24, what is the value of x when y=7?

Answer 1

I amAnswer:

9. y = 21

10. x = 28

11. y = 3

12. x = 16

Explanation:

If they vary directly, they can be solved using a rule of three.

9. If y = 14 when x = 8, find y when x = 12.

14 - 8

y - 12

8y = 14*12

8y = 168

y = 168/8

y = 21

10. If y = 6 when x = 24. What is the value of x when y = 7?

6 - 24

7 - x

6x = 24*7

Simplifying by 6

x = 4*7

x = 28

11. Find y when x = 15, if y = 6 when x = 30

y - 15

6 - 30

30y = 15*6

30y = 90

y = 90/30

y = 3

12. Find x when y = 14, if y = 7 when x = 8.

7 - 8

14 - x

7x = 14*8

Simplifying by 7

x = 2*8

x = 16