#### Answer

slope = $0$
The line through the points is horizontal.

#### Work Step by Step

RECALL:
The slope of the line that passes through the points $(x_1, y_1)$ and $(x_2, y_2)$ is given by the formula:
$m=\dfrac{y_2-y_1}{x_2-x_1}$
Solve for the slope of the line that passes through the two given points using the formula above to obtain:
$m=\dfrac{5-5}{-1-(2)}=\dfrac{0}{-3}=0$
A line with a slope of zero is horizontal.