The midpoint can be found by using the formula of x1+x2/2 and y1+y2/2 which gives you the midpoint coordinates.

For example, if the coordinates of A are (-2, 5) and the coordinates of B are (2, 3), then you would simple do -2+2/2 to get the x coordinate of the midpoint, and the same thing for the y coordinate which would be 5+3/2. The coordinate of the midpoint would then be (0, 4)