SOLUTION: Ok yesterday we were working ont his homework in class, but for the sake of time, on the notes we took we skipped the last two on the sheet. When I can upon this question I realiz

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: Ok yesterday we were working ont his homework in class, but for the sake of time, on the notes we took we skipped the last two on the sheet. When I can upon this question I realiz      Log On


   

Question 122500: Ok yesterday we were working ont his homework in class, but for the sake of time, on the notes we took we skipped the last two on the sheet. When I can upon this question I realized we had done nothing like it in our notes that day.
The question is:
If y varies directly with x and y is 40 when x is 25, what is x when y is 36?
Please help and thank you for your time!
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
When y varies directly with x, then the equation is,
y=kx
From your example,
y=kx
40=k%2825%29
k=40%2F25
k=8%2F5
So your equation becomes,
y=%288%2F5%29x
When y=36,
36=%288%2F5%29x
x=%285%2F8%2936
x=45%2F2