The x coordinates of the given points are -2 and -4
Add them up: -2 + (-4) = -6
Divide the result in half: -6/2 = -3
This is the x coordinate of the midpoint.
The steps to compute the y coordinate will look the same, but dealing with the y coordinates of course.
Add y coordinates: -2 + 7 = 5
Divide in half: 5/2 = 2.5
Answer: midpoint = (-3, 2.5)