Answer:
(x1+x2)/2, (y1+y2)/2
Explanation:
You have two points. P1 and P2. Midpoint's x coordinate is the sum of x coordinates of P1 and P2 divided by 2. Midpoint's y coordinate is similarly the sum of P1 and P2 y coordinates, divided by 2.
Generally;
m = (P1.x+P2.x)/2, (P1.y+P2.y)/2