For this question we will use the formula for the slope of a line passing through two points:
[tex]s=\frac{y_2-y_1}{x_2-x_1}\text{.}[/tex]Substituting the given points we get:
[tex]s=\frac{-1-2}{1-3}=\frac{-3}{-2}=\frac{3}{2}\text{.}[/tex]Answer:
[tex]\frac{3}{2}\text{.}[/tex]