a) How can you produce a big-O estimate for a function that is the sum of different

Question:

a) How can you produce a big-O estimate for a function that is the sum of different terms where each term is the product of several functions?
b) Give a big-O estimate for the function f (n) = (n! + 1)(2n + 1) + (nn−2 + 8nn−3)(n3 + 2n). For the function g in your estimate f (x) is O(g(x)) use a simple function of smallest possible order.