Let f(x)=-3x^2+x-4, g(x)=5x^2-3x-8, and h(x)=5x^2+5x+1. Express f(x)+g(x)+h(x) as a single polynomial, with the terms in order by decreasing degree.
Just finish this:
(3x^2 + 5x^2 + 5x^2) + ( x -3x +5x) + ( 4-8+1)