P(x₁,7) & Q(10,y₁)
Calculate the midpoint of the segment PQ, means we have to calculate R, the pairs of this midpoint. But this midpoint is known R(6,4) so let's use it to calculate respectively x & y in P(x₁,7) & Q(10,y₁)
x of midpoint = (x₁+x₂)/2 & y of midpoint = (y₁+y₂)/2
1) x=(x₁+10)/2, but x=6, hence 6=(x+10)/2 and x = 2
2) y=(7+y)/2, but y=4, hence 4=(7+y)/2 and y= 1
