1) = (x^4-3x^3)(2+x^3) = 2x^4+x^7-6x^3-3x^6=x^7-3x^6+2x^4-6x^3
2)=a^2b^2-4a^4-4b^4+16a^2b^2=17a^2b^2-4a^4-4b^4
