In 2012, the population of Houston, Texas, was about 2 × 106 and the population of San Marcos, Texas, was about 5 × 104. Which of the following statements is true?

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.