just plug and chug
AEx^2 + BEx^3 + CEx
+ AFx + BFx^2 + CF
now add 'em up
(A*x + B*x^2 + C)*(E*x + F)
2 answers
(A*x + B*x^2 + C)*(E*x + F)
A*x (E*x) + A*x(F) + B*x^2(E*x )+ B*x^2(F)+C(E*x )+ C(F)
A*x (E*x) + A*x(F) + B*x^2(E*x )+ B*x^2(F)+C(E*x )+ C(F)