Solution:
Given;
[tex]midpoint(-9,8),endpoint(-1,1)[/tex]
Using the midpoint formula;
[tex]midpoint(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})[/tex]
Thus;
[tex]\begin{gathered} \frac{x_1+x_2}{2}=-9;x_2=-1 \\ \\ x_1-1=2(-9) \\ \\ x_1=-18+1 \\ \\ x_1=-17 \end{gathered}[/tex]
Similarly;
[tex]\begin{gathered} \frac{y_1+y_2}{2}=8;y_2=1 \\ \\ y_1+1=2(8) \\ \\ y_1=16-1 \\ \\ y_1=15 \end{gathered}[/tex]
Thus, the other endpoint is;
[tex](-17,15)[/tex]
