Ab has endpoints at a(6,5) and b(2,7).

what are the coordinates of the midpoint, m, of the segment?

enter your answer as an ordered pair, like this: (42, 53)

Let x have probability generating function gx (s) and let un generating function u(s) of the sequence uo, u1, satisfies p(x > n). show that the (1- s)u(s) = 1 - gx(s), whenever the series defining these generating functions converge.