1.6a^3-8a^2-4a

题目

1.6a^3-8a^2-4a
2.-x^3y^3-2x^2y^2+xy
3.ma-mb+m^2+mn+na+nb

答案

1.2a(3a^2-4a-2)
2.-(x^3y^3+2x^2y^2-xy )
=-xy(x^2y^2+2xy-1)