1) To find the slope of the line that passes through those points, we'll need to use the Slope Formula
[tex]\begin{gathered} m=\frac{y_2-y_1_{}}{x_2-x_1} \\ m=\frac{-4-(-2)}{5-15}=\frac{-4+2}{-10}=\frac{-2}{-10}=\frac{-1}{-5}=\frac{1}{5} \end{gathered}[/tex]Note that the slope is the measure of how steep is the line between those points.
2) That is the answer.