Answer
$f^{-1}(x)=4x+3$
Work Step by Step
The given function, $
f(x)=\dfrac{x-3}{4}
,$ is equivalent to
\begin{array}{l}\require{cancel}
y=\dfrac{x-3}{4}
.\end{array}
Interchanging the $x$ and $y$ variables, and then solving for $y$ result to
\begin{array}{l}\require{cancel}
x=\dfrac{y-3}{4}
\\\\
x(4)=y-3
\\\\
4x=y-3
\\\\
4x+3=y
\\\\
y=4x+3
.\end{array}
Hence, the inverse function is $
f^{-1}(x)=4x+3
$.
