One endpoint of a line segment is (4,3) and its midpoint is (2,9). What is the sum of the coordinates of the other endpoint?
We have this
( 4 + x) / 2 = 2 (3 + y) / 2 = 9
4 + x = 4 3 + y = 18
x = 0 y = 15
So...the other endpoint is (0,15) and the sum of its coordinates is 15
+612 
