Explanation:
1. The midpoint formula says the coordinates of the midpoint are the average of the endpoints.
x = (x₁ + x₂) / 2
y = (y₁ + y₂) / 2
I'll do #2 and #3 as examples.
2. x = (-4 + 10) / 2 = 3
y = (6 + -10) / 2 = -2
So the midpoint is (3, -2).
3. x = (-3 + -6.5) / 2 = -4.75
y = (-8 + -4.5) / 2 = -6.25
So the midpoint is (-4.75, -6.25).