Question

which of the following best describes the slope of the line below? a. positive b. negative c. undefined d. zero

Explanation:

A horizontal line has a slope calculated by the formula $m=\frac{y_2 - y_1}{x_2 - x_1}$. For a horizontal line, the $y$-values of any two points are the same, so $y_2 - y_1 = 0$. Thus, the slope $m = \frac{0}{x_2 - x_1}=0$ (as long as $x_2
eq x_1$). The line in the graph is horizontal, so its slope is zero.

Answer:

D. Zero