Viviana wants to wrap a gift in a box that is 5 inches by 3 inches how much wrapping paper will she need? assume that the paper does not overlap

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.