2(xy^2+3y^3-x^2y)-(-2x^2y+y^3+xy^2)-4y^3等于多少x=2,y=3
问题描述:
2(xy^2+3y^3-x^2y)-(-2x^2y+y^3+xy^2)-4y^3等于多少x=2,y=3
答
∵x=2,y=3∴2(xy^2+3y^3-x^2y)-(-2x^2y+y^3+xy^2)-4y^3=2xy²+6y³-2x²y+2x²y-y³-xy²-4y³=y³+xy²=y²(x+y)=3²(2+3)=45