We have the following:
[tex]\begin{gathered} x_1+\frac{1}{r+1}\cdot(x_2-x_1) \\ y_1+\frac{1}{r+1}\cdot(y_2-y_1) \end{gathered}[/tex]replacing:
for x:
[tex]\begin{gathered} x=-8_{}+\frac{1}{4+1}\cdot(7-(-8)) \\ x=-8+\frac{1}{5}\cdot(7+8)=-8+3=-5 \end{gathered}[/tex]for y:
[tex]\begin{gathered} y=8_{}+\frac{1}{4+1}\cdot(-7-(8)) \\ y=8+\frac{1}{5}\cdot(-788)=8-3=5 \end{gathered}[/tex]The coordinates is: (-5, 5)