Answer
$\color{blue}{\left\{-5, 0, 4\right\}}$
Work Step by Step
RECALL:
Zero-Factor Property:
If $ab = 0$, then either $a=0$ or $b=0$ or both are $0$.
Use the property above to obtain:
\begin{array}{ccccc}
&x=0 &\text{or} &x-4=0 &\text{or} &x+5=0
\end{array}
Solve each equation to obtain:
$x=0$
or
$x-4=0
\\x=0+4
\\x=4$
or
$x+5=0
\\x=0-5
\\x=-5$
Thus, the solution set is $\color{blue}{\left\{-5, 0, 4\right\}}$.