Answer:
(25,-26)
Explanation:
difference between the two points in x and y coordinates are
x = 10 - (-5) =15, y = -9 - 8 = -17,
so to get to the other endpoint you need to add another
x = 15 and y = -17 to the midpoint, (10,-9).
10+15 = 25 for x and -9 - 17 is -26 for y.