Answer
$f^{-1}(x)=\frac{3-2x}{x-2}$
Work Step by Step
$f(x)=\frac{2x+3}{x+2},$
$y=\frac{2x+3}{x+2},$
a. $x=\frac{2y+3}{y+2},$
$x(y+2)=2y+3,$
$xy+2x=2y+3,$
$xy-2y=3-2x,$
$y(x-2)=3-2x,$
$y=\frac{3-2x}{x-2}=f^{-1}(x),$
b. Domain of $f(x)$ is $x\in \mathbb{R} \ne -2$ and Domain of $f^{-1}(x)$ is $x\in\mathbb{R} \ne 2$