If f(x)=4x−5f(x) = \frac{4}{x-5}f(x)=x−54, find f−1(x)f^{-1}(x)f−1(x).
f−1(x)=x−54f^{-1}(x) = \frac{x-5}{4}f−1(x)=4x−5
f−1(x)=4+5xxf^{-1}(x) = \frac{4+5x}{x}f−1(x)=x4+5x
f−1(x)=4x+5f^{-1}(x) = \frac{4}{x} + 5f−1(x)=x4+5
f−1(x)=5−4xf^{-1}(x) = 5 - \frac{4}{x}f−1(x)=5−x4