Answer:
The coordinates of B are (-8,25).
Step-by-step explanation:
Consider the completer question is " M(−2, 10) is the midpoint of AB. If A has coordinates (4, −5), what are the coordinates of B".
Let coordinates of B are (a,b).
Formula for midpoint:

Midpoint of A and B is

It is given that M(−2, 10) is the midpoint of AB.

On comparing both sides we get

Multiply both sides by 2.

Subtract 4 from both sides.

The value of a is 8.
Similarly,

Multiply both sides by 2.

Add 5 on both sides.

Therefore, the coordinates of B are (-8,25).