For the midpoint, you have to add each individual X coordinate and Y coordinate, and divide them by 2.
So:
[tex]\begin{gathered} (\frac{(x1+x2)}{2},\frac{(y1+y2)}{2}) \\ \\ =(\text{ }\frac{-1+3}{2},\text{ }\frac{-3+2}{2}) \\ \\ =(\frac{2}{2},\text{ -}\frac{1}{2}) \\ \\ =(1,\text{ -}\frac{1}{2}) \end{gathered}[/tex]
The midpoint will be in 1, - 1/2
