Given the points A=(5,-7) and B=(8,-12), we can find the midpoint in the following way:
[tex]\begin{gathered} M(A,B)=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2}) \\ \Rightarrow M(A,B)=(\frac{5+8}{2},\frac{-7-12}{2}) \\ \Rightarrow M(A,B)=(\frac{13}{2},-\frac{19}{2}) \end{gathered}[/tex]Therefore, the midpoint is (13/2,-19/2)