SOLUTION: I need help with this: find the inverse of the function f(x)=(5x+4)/7

Algebra ->  Functions -> SOLUTION: I need help with this: find the inverse of the function f(x)=(5x+4)/7      Log On


   

Question 87826: I need help with this: find the inverse of the function f(x)=(5x+4)/7
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
find the inverse of the function f(x)=(5x+4)/7
y = f(x)
:
y = %28%285x%2B4%29%29%2F7
:
Swap x and y and solve for y:
%28%285y%2B4%29%29%2F7 = x
:
Mult both sides by 7 and you have:
5y + 4 = 7x
:
Subtract 4 from both sides:
5y = 7x - 4
:
Divide both sides by 5:
y = %28%287x-4%29%29%2F5
:
f%5E-1(x) = %28%287x-4%29%29%2F5