Answer
slope = $0$
The line through the two given points is horizontal.
Work Step by Step
RECALL:
(1) The slope $m$ of a line that passes through the points $(x_1, y_1)$ and $(x_2, y_2)$ can be found using the formula:
$m=\dfrac{y_2-y_1}{x_2-x_1}$
(2) A line with a positive slope rises from left to right. A line with a negative slope falls from left to right.
(3) A line with a slope of 0 is horizontal. A line with an undefined slope is vertical.
Solve for the slope of the line using the formula in (1) above to obtain:
$m=\dfrac{-1-(-1)}{3-4}=\dfrac{0}{-1}=0$
The slope is 0 therefore the line through the given points is horizontal.