Answer
$(f~o~g)^{-1}=\frac{1}{2}x+\frac{1}{2}$
Work Step by Step
$f~o~g=f(g(x))=f(2x-5)=2x-5+4=2x-1~~$ (Replace $f~o~g$ by $y$)
$y=2x-1~~$ (Interchange $x$ and $y$):
$x=2y-1$
$x+1=2y$
$y=\frac{1}{2}x+\frac{1}{2}$
$(f~o~g)^{-1}=\frac{1}{2}x+\frac{1}{2}$
