First we will find the x coordinate.
x1+x2 / 2 = the x coordinate of the midpoint.
-9 + x2 / 2 = 10
x2/2 -4.5 = 10
x2/2 = 14.5
x2 = 29
Now the y coordinate:
y1+y2 /2 = y coordinate of the midpoint
7 + y2 / 2 = -3
y2/2 + 3.5 = -3
y2/2 = -6.5
y2 = -13
So the other endpoint is (29,-13)
I hope i am right :)
