Answer
$m=0$
Work Step by Step
RECALL:
The slope $m$ of a line that passes through the points $(x_1, y_1)$ and $(x_2, y_2)$ is given by the formula:
$m=\dfrac{y_2-y_1}{x_2-x_1}$
Substitute the x and y coordinates of the given points to obtain:
$m=\dfrac{4-4}{0-5}
\\m=\dfrac{0}{-5}
\\m=0$