x³+y³=40,xy=2.

已知x+y=2,xy=1/2,求x³y+2x²y²+xy³ 2x+y=0,求4x²+2xy(x+y)+y³ 若xy³=-3,则-xy【x²y五次方-xy³-y】的值为 已知x+y=5,xy=3,x³+y³=(x+y)(x²-xy+y²),则1/x& 一.x-y=2,则x²-2xy+y²= 二.x-y=-1,xy=3,则x³y-2x 已知x^2-xy=60´xy-y^2=40,求代数式x^2-y^2和x^2.-2xy+y^2的 已知x^2-xy=60´xy-y^2=40,求代数式x^2-y^2和x^2.-2xy+y^2的值 先化简再求值,3xy²(xy+2y²-x²)+3x³y²,其中x=2, x-xy=40,xy-y= -20,求代数式x-y和x+y-2xy 已知:x-xy=40,xy-y=-20,求代数式x-y和x+y-2xy的值. 已知：x-y=1,xy=-2.求：(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 x-y=1,xy=2.求：(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值