Question 1
[tex]\left(\frac{-5+2}{2}, \frac{5-5}{2} \right)=\boxed{\left(-\frac{3}{2}, 0 \right)}[/tex]
Question 2
Let the coordinates of the other endpoint be (x,y).
[tex]\left(\frac{x + 4}{2}, \frac{y+8}{2} \right)=( - 6,4) \\ \\ \implies \frac{x + 4}{2}=6 \implies x= - 16\\ \\ \frac{y+8}{2}=4 \implies y=0[/tex]
So, the coordinates of the other endpoint are (-16,0).
