计算(2X^3-3X^2Y-2XY^2)-(x^3-2xy^2+y^3)+(-x^3+3x^2y-y^3)的值,其中,x=1/2,y=1

问题描述:

计算(2X^3-3X^2Y-2XY^2)-(x^3-2xy^2+y^3)+(-x^3+3x^2y-y^3)的值,其中,x=1/2,y=1

(2X^3-3X^2Y-2XY^2)-(x^3-2xy^2+y^3)+(-x^3+3x^2y-y^3)=2x^3-3X^2Y-2XY^2-X^3+2XY^2-Y^3-X^3+3X^2Y-Y^3=2x^3-X^3-X^3-3X^2Y+3X^2Y-2XY^2+2XY^2-Y^3-Y^3=-2Y^3=-2×(1)^3=-2