Answer
$f^{-1}(x)=\dfrac{x+2}{3}$
Work Step by Step
$f(x)=3x-2$
Substitute $f(x)$ by $y$:
$y=3x-2$
Solve this expression for $x$:
$y+2=3x$
$\dfrac{y+2}{3}=x$
$x=\dfrac{y+2}{3}$
Interchange $x$ and $y$:
$y=\dfrac{x+2}{3}$
Substitute $y$ by $f^{-1}(x)$:
$f^{-1}(x)=\dfrac{x+2}{3}$
