Find the nth term of the sequence
20, 30, 42, 56, 72
Please hurry it's due in an hour!​

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.