Given any 2 point P(m,n) and Q(k,l),
the coordinates of the midpoint of the line segment PQ are given by the formula:
[tex]M_{PQ}=( \frac{m+k}{2} , \frac{n+l}{2})[/tex],
Thus, given the points with coordinates (a,2b) and (-3a,4b),
the midpoint is
[tex]( \frac{a+(-3a)}{2} , \frac{2b+4b}{2} )=( \frac{-2a}{2} , \frac{6b}{2} )=(-a, 3b)[/tex]
Answer: (-a, 3b)
