(1/x-y-1/x+y)*x²-2xy+y²/(y+1)²-(y-1)²
【(1)/(x-y)+(1)/(x-y)】÷(2x)/(x²-2xy+y²)
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
计算:1、(xy分之x²-y²)×(x-y分之x)-(y分之x);
x²+xy/(x-4y)(x+y),其中x=4,y=-1
多项式因式分解 1,(x-y)³-(x-y)²(x+y) 2,x(x²-xy)-(4x
因式分解(xy-1)²+(x+y-2)(x+y-2y)怎么做哇?
1、y-x/x²-y²
若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy(
已知X²+Y²+X²Y²-4XY+1=0 求:(X-Y)^2008-(XY)^2