SOLUTION: if y caries directly as the square root of x and x=25 when y=-15, find x when y=-108 can u just show me how to solve the problem, not the answer??? thanks!!!!!

Question 280666: if y caries directly as the square root of x and x=25 when y=-15, find x when y=-108
can u just show me how to solve the problem, not the answer??? thanks!!!!!
Answer by jsmallt9(3758) (Show Source): You can put this solution on YOUR website!
The phrase "y varies directly as (something)" it means:
y = k*(something)
where k is some constant.
So your equation is:

Now you

use this equation and the given x,y pair (25, -15) to find out what k is.
rewrite the equation with the value you found for k.
use the new equation to find the x for y = -108.

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