Question

Find a formula for the inverse of the function
f(x)=1+8x/8−5x.

f^[−1](Q) =

Answer 1

f = (1+8x)/(8-5x)
swap variables and you have

x = (1+8f)/(8-5f)
x(8-5f) = 1+8f
8x - 5xf = 1 + 8f
-5xf - 8f = 1 - 8x
-(5x+8)f = (1-8x)
f = (8x-1)/(5x+8)