化简(x²-y²/xy)²÷(x+y)²×(x/x-y)³求当x=3
x²/xy-x/y
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)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=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
化简x-y分之x + x³-2x²y+xy²分之y³ ÷ y²-x
[x(x²y²-xy)-y(x²-x³y)]÷3x²y
【x(x²y²-xy)-y(x²-x³y)】÷3x²y
因式分解:[x(x²y²-xy)-y(x²-x³y)]÷3x²y
x/y=3,求x²+y²-xy/x²-y²的值.
2x+y=0,求4x²+2xy(x+y)+y³
2x²-3xy=y²=0(x,y不得o)求x/y+y/x
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)