求多项式5-2xy^2-4x^3y与5+2x^3y-2xy^2的差?
问题描述:
求多项式5-2xy^2-4x^3y与5+2x^3y-2xy^2的差?
答
(5-2xy^2-4x^3y)-(5+2x^3y-2xy^2) 去括号
=5-2xy^2-4x^3y-5-2x^3y+2xy^2
=5-5-2xy^2+2xy^2-4x^3y-2x^3y
=-6x^3y