Remember that the formula to calculate the midpoint between two points is given by
[tex]M(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})[/tex]
substitute given coordinates
[tex]\begin{gathered} M(\frac{-8-7}{2},\frac{-7-8}{2}) \\ \\ M(-\frac{15}{2},-\frac{15}{2}) \end{gathered}[/tex]
The answer is option B
