One endpoint and the midpoint of a segment are given. Find the coordinates of the other endpoint. Show all your work.

Question

A. Endpoint: (-1,9)
Midpoint: (-9,-10)
Endpoint: _______


B. Endpoint: (9,-10)
Midpoint: (4,8)
Endpoint: ________

Answer 1

For x,
-9 is 8 below -1
So, the other end is 8 below -9, or -17

Same for y.

The other problem is the same method.

Answer 2

A.(x,y), (-9,-10), (-1,9).
-9-x = 1/2(-1-x).
-18-2x = -1-x.
-x = 17.
X = -17.

-10-y = 1/2(9-y).
-20-2y = 9-y.
-y = 29.
Y = -29.

B. (x,y), (4,8), (9,-10).
4-x = 1/2(9-x).
Multiply both sides by 2, and Solve for x.

8-y = 1/2(-10-y).