Answer: (2,-16)
Explanation
If there is one endpoint and a midpoint, the other endpoint would be the same amount of units away from the midpoint as the first midpoint.
The first endpoint has an x of -2, while the midpoint has an x of 0. The difference between these two is 2, so the other endpoint would be 2 units away from the midpoint (at x=2)
The first endpoint has a y of -4, while the midpoint has a y of -9. These are 5 units apart, which means the other endpoint would be 5 away from the midpoint (y=-16)
So combining the two points gets you the answer, which would be (2,-16)