Answer:
(-7 1/2, -7 1/2)
Explanation:
Midpoint is 1/2 the x difference and 1/2 the y difference.
The x distance is the absolute values (can't have a negative distance) of
(x2 - x1) / 2 and the y distance is (y2 - y1) / 2.
So
Dx = (-8 -(-7)) / 2 = -1 / 2 or 1 / 2 and
Dy = (-7 - (-8)) / 2 = 1 /2 or 1 / 2
pick the point with the largest -x or smallest +x value and add distance
x = -8 + 1/2 = -7 1/2
pick the point with the largest -y or smallest +y value and add distance
y = -8 + 1/2 = -7 1/2
so midpoint is (-7 1/2, -7 1/2)