求[(x+y)²(x-y)²+16x²y²]/[(x+y)(x-y)]-8xy的

x²/xy-x/y 已知x²+y²-8x+6y+25=0,求（x-y+4xy/x-y）（x+y-4xy/x+y） 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 已知非零有理数x,y满足x²-4xy+4y²=0,求x-y/x+y-y-x/x+y的值. x/y=3,求x²+y²-xy/x²-y²的值. 已知x+y=1,xy=-二分之一,求x（x+y)(x-y)-x(x+y)² 若正数x,y满足x²-y²=2xy,求（x-y)/(x+y)的值 正数x,y满足x²-y²=2xy,求x-y/x+y的值 若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值 计算：(xy-x²)×x-y/xy 4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/（x+2y-12Y²/x-2y)的值 [-xy/(x-y)²]²×(y²-xy/x)³