(a^3m)^2-(b^2n)^3+(a^2m)X(b^3n)=a^6m-b^6n+(a^2m)X(b^3n)=(a^2m)^3-(b^3n)^2+(a^2m)X(b^3n)=(a^2m)[(a^2m)^2-(b^3n)]-(b^3n)^2