Answer:
B = 2M -A
Step-by-step explanation:
For given endpoint A and midpoint M, the other endpoint B can be found using the definition of the midpoint:
M = (A+B)/2
2M = A+B . . . . . multiply by 2
2M-A = B . . . . . subtract A
The second endpoint can be found by subtracting the given endpoint from twice the midpoint:
B = 2M -A
