Answer
$[3, 6]$
Refer to the image below for the graph.
Work Step by Step
Add $4$ to each part of the inequality to obtain:
$\begin{array}{ccccc}
&5+4 &\le &3x-4+4 &\le &14+4
\\&9 &\le &3x &\le &18
\end{array}$
Divide $3$ to each part of the inequality to obtain:
$\begin{array}{ccccc}
&\dfrac{9}{3} &\le &\dfrac{3x}{3} &\le &\dfrac{18}{3}
\\&3 &\le &x &\le &6
\end{array}$
Thus, the solution set is $\bf[3, 6]$.
To graph this solution set, plot solid dots at $3$ and $6$ then shade the region in between.
(refer to the attached image in the answer part above for the graph)