You just want to find the middle of the pair of x coordinates and the pair of y coordinates.
Or,
The number in the middle of -2 and 4, and also 5 and -9.
Number in between -2 and 4: The distance between them is 6, so the number must be 3 away from both of them. -2 + 3 = 1.
Number in between 5 and -9: The distance is 14. Number must be 7 away from both. -9 + 7 = -2
So the midpoint would be:
(1, -2)