Answer
$m=0$
Work Step by Step
Using $m=\dfrac{y_1-y_2}{x_1-x_2}$ or the Slope Formula, then the slope of the line containing the given points, $\left(
5,-2
\right) \text{ and } \left(
-4,-2
\right)$, is
\begin{array}{l}
m=\dfrac{-2-(-2)}{5-(-4)}
\\\\
m=\dfrac{-2+2}{5+4}
\\\\
m=\dfrac{0}{9}
\\\\
m=0
.\end{array}