Find inverse function.
[tex]f(x)= \frac{x-1}{5}
\\y= \frac{x-1}{5}
\\x= \frac{y-1}{5}
\\y-1=5x
\\y=5x+1
\\f^{-1}(x)=5x+1
\\
\\f(x)= \frac{x-1}{5}
\\f^{-1}(x)=5x+1 \\ \\f(f^{-1}(x))=f(5x+1)= \frac{(5x+1)-1}{5} = \frac{5x}{5}= x \\ \\ f^{-1}(f(x))=f^{-1}(\frac{x-1}{5} )=5\frac{x-1}{5}+1=x-1+1=x[/tex]
