## Precalculus (10th Edition)

$m=0$ Refer to the graph below.
The slope of the line can be determined by the equation: $m=\dfrac{y_2-y_1}{x_2-x_1}$ where $(x_1, y_1)$ and $(x_2, y_2)$ are two given points on the line. Here, we can substitute the coordinates of the points $(4,2)$ and $(-5,2)$ to obtain: $m=\dfrac{2-2}{-5-4)}=\dfrac{0}{-9}=0$ Plot the points and connect them using a line.