The point with coordinates (5,-11) is the midpoint of the segment with one endpoint at (9,7). Find the sum of the coordinates of the other endpoint.
Let the other endpoint be ( x, y)
And we have that
(9 + x) / 2 = 5 ( 7 + y) / 2 = -11
9 + x = 5*2 7 + y = -11*2
9 + x =10 7 + y = -22
x = 10 -9 = 1 y = -22 - 7 = -29
(x, y ) = ( 1, -29)
