Answer:
(-16, 0)
Explanation:
You want the other endpoint of the segment with midpoint (-6, 4) and endpoint (4, 8).
Setup
The midpoint of a line segment has coordinates that are the average of the coordinates of the end points.
M = (A +B)/2 . . . . midpoint M of segment AB
2M = A +B . . . . . multiply by 2
B = 2M -A . . . . . solved for the other end point
B = 2(-6, 4) -(4, 8) . . . . substitute given coordinates
Solution
B = (2(-6) -4, 2(4) -8) = (-16, 0)
The other end point of the segment is (-16, 0).