Find the coordinates of the other endpoint of the​ segment midpoint ​(​18,-18​), endpoint ​(​19,-15​)

Question

the other answer is an ordered pair

Answer 1

The coordinates of the midpoint of two other points is the average of their coordinates.

So let the coordinate of the missing endpoint be (x,y).

Then: the average x coordinate is (x+19)/2=18 and the average y coordinate is (y-15)/2=-18.

From these equations: x+19=36, so x=36-19=17; y-15=-36, y=15-36=-21.

Therefore the coordinates of the endpoint is (17,-21).