(已知:x+y=1/2.xy=1,求x³y+2x²y²+xy³

.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 (已知:x+y=1/2.xy=1,求x³y+2x²y²+xy³ 已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y) 已知xy-x-y=11,求(xy-1)^2+(x+y-2)(x+y-2xy)的值. 已知x+y=-1,xy=-2,求代数式-5（x+y)+(x-y)+x(xy+y)的值 已知x+y=1,xy=-二分之一,求x（x+y)(x-y)-x(x+y)² 已知x+y=1,xy=-二分之一,求x（x+y)(x-y)-x(x+y)² 已知x(x-1)-(x²-y)=-3,求(x²y+xy²)÷xy-2y 已知|x+y+1|+|xy+3|=0,求代数式xy^3+X^3y 已知X、Y属于R+,且XY-(X+Y)=1,求XY的范围 已知x y=1,xy=-3,求2xy-4x 4(y-2(xy-x)) 已知x×x×y×y+x×x+y×y+1=4xy,求x,y的值快 已知x(x+1)-(x²+y)=3求2/x²+y²-xy 已知x(x-1)-(x^2-y)=-3.求x^2+y^2-2xy 已知x+y=-1,xy=-2,求代数式-5（x+y)+(x-y)+2(xy+y)的值 已知1/x-1/y=2001,求分式x-xy-y/x-y的值 已知x>y>0,xy=1,求x^2+y^2/x-y的最小值. 已知正数x、y满足xy-x-y=1,求x+y的最小值