化简求值(0.2x^3-x^2y-xy^2)-(xy^2-x^2y-0.5x^3)+0.3x^3其中x=-3y=-2如题_数学解答

化简求值(0.2x^3-x^2y-xy^2)-(xy^2-x^2y-0.5x^3)+0.3x^3其中x=-3y=-2
如题

人气：216 ℃　时间：2020-04-03 16:02:54

解答

（0.2x^3-x^2y-xy^2)-(xy^2-x^2y-0.5x^3)+0.3x^3
=x^3（0.2+0.5+0.3）-x^2y+x^2y-xy^2-xy^2
=x^3-2xy^2
=-27-2*36
=-99