Question

A line segment has an endpoint at (-4,10) and a midpoint at (-8,0). Find the other endpoint.

Answer 1

(-12, -10)

Explanation:

Midpoint M is the average of endpoints A and B:

M = (A +B)/2

2M = A + B . . . . . . multiply by 2; next, subtract A

B = 2M - A . . . . . . the missing endpoint can be found this way

B = 2(-8, 0) -(-4, 10) = (2(-8)+4, 2(0)-10) = (-12, -10)