Question

Find the coordinates of the other endpoint when you are given the midpoint (point M) and one of the endpoints (point P).

P = (10, 6) and M = (-4, 8)

a.(-18, 10)
b.(2, 10)
c.(3, 7)

Answer 1

Since midpoint coordinates are just the average of the endpoint coordinates we can say x is:

(10+x)/2=-4

10+x=-8

x=-18

So we really don't need to go any further as x=-18 is only present in answer a. (-18,10), but we can make sure...

(6+y)/2=8

6+y=16

y=10 so it is confirmed the other endpoint is (-18,10)