已知x-y=1,xy=2,求x³y-2x²y²+xy³.

已知x+y=2,xy=1/2,求x³y+2x²y²+xy³ 已知xy=-1,求代数式-1/2x(xy²-y-x³y的四次方) 已知X²+Y²+X²Y²-4XY+1=0 求:（X-Y)^2008-(XY)^2 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 已知实数xy满足x²﹢y²-xy+2x-y+1=0求xy 已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y 已知x:y=3:2,求(x²+3xy)/(xy+2xy) 已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
2x+y=0,求4x²+2xy(x+y)+y³ 已知x-y=1/2,xy=8.求-1/2x³y-1/2xy³+x²y²的值. 已知x+y=5,xy=1求2x³y+4x²y²+2xy³ 已知x-y=1,xy=2,求x³y-2x²y²+xy³的值