Answer:
B = (6, 4)
Step-by-step explanation:
You know that the midpoint is calculated as ...
M = (A +B)/2
Solving this for B, we find ...
2M = A + B
B = 2M - A
Filling in the coordinate values, we get ...
B = 2(5, -2) -(4, -8) = (2·5-4, 2(-2)+8)
B = (6, 4)
