Question 135589
The x-coordinate of the midpoint of the segment joining ({{{x[1]}}},{{{y[1]}}}) and ({{{x[2]}}},{{{y[2]}}}) is given by {{{x[m]=(x[1]+x[2])/2}}}, and the y-coordinate is given by {{{y[m]=(y[1]+y[2])/2}}}.  Just plug in the numbers and do the arithmetic.