Answer
$m=-\frac{3}{4}$
Work Step by Step
To find the slope of an line you need to take a look at two points. With these two points you will fill in the formula of the differences quotient:$ \frac{y2-y1}{x2-x1}$. The numbers 1&2 indicate the points the number 2 is the one on the right. Number one therefore is the left point.
In this example this would be: $\frac{-1-2}{3--1}=-\frac{3}{4}$ since we have the points A(-1/2) and B(3/-1).