Answer
$\left[-\dfrac{4}{5}, \dfrac{9}{5}\right]$
Refer to the image below for the graph.
Work Step by Step
Add $4$ to each part of the inequality to obtain:
$\begin{array}{ccccc}
&-8+4 &\le &5x-4+4 &\le &5+4
\\&-4 &\le &5x &\le &9
\end{array}$
Divide $5$ to each part of the inequality to obtain:
$\begin{array}{ccccc}
&\dfrac{-4}{5} &\le &\dfrac{5x}{5} &\le &\dfrac{9}{5}
\\&\dfrac{-4}{5} &\le &x &\le &\dfrac{9}{5}
\end{array}$
Thus, the solution set is $\bf\left[\frac{-4}{5}, \frac{9}{5}\right]$.
To graph this solution set, plot solid dots at $\dfrac{-4}{5}8$ (or $-0.8$) and $\dfrac{9}{5}$ (or $ 1.8$) then shade the region in between.
(refer to the attached image in the answer part above for the graph)