f(x)=9x^3+2x^2-5x+4
g(x)=5x^3-7x+4
1. Work out the common terms for Ex:
9x^3-5x^3=4x^3
-5x--(+) 7x= 2x
4-4=0
2. Write out new Expression:
4x^3+2x^2+2x (Keep the 2x^2 Because no other common terms with it and put them order of descending power ^3 ^2 ^1 like so)
3. Factoring
2x(2x^2+x+1) Factor out 2x
