Answer
$m=-3$
Work Step by Step
Using $m=\dfrac{y_1-y_2}{x_1-x_2}$ (or the Slope Formula), the slope, $m$, of the line through $(
2,8
) \text{ and } (
6,-4
)$ is
\begin{array}{l}
m=\dfrac{8-(-4)}{2-6}
\\\\
m=\dfrac{8+4}{2-6}
\\\\
m=\dfrac{12}{-4}
\\\\
m=-3
.\end{array}