The inverse of this function is f(x) =

To find the inverse of any function, start by switching the x and f(x) term. Then solve for the new f(x). The result will be the inverse function. The step-by-step process is below for you.
f(x) =
----> Switch the x and f(x)
x =
----> Muliply both sides by 3
3x = -15 + 4f(x) ----> Add 15 to both sides
3x + 15 = 4f(x) ----> Divide both sides by 4.
f(x) =
