[x/(x-y)]·[y²/(x+y)]-[x^4y/(x^4-y^4)]÷[x²/(x²
(x-2y)²+(2x-4y)(x+y)+(x+y)²
2.(x+y)²(x-y)²-(x-y)(x+y)(x²+y²)
(3x-y)²-2x(4x-5y)-(x+2y)²
(2x-y)²-4(x-y)(x+2y)
化简:(2x-y)²-4(x-y)(x+y)
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
计算4(x+y)^5(x-y)^4÷[2(x+y)³*(y-x)²]
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
【(2x+y)²-y(y+4x)-8x】÷2x,其中x=100
(x+y)²+4(x+y)-5
计算 [12(x+y)³(y-x)]³÷[4(x+y)²(x-y)]²
(x²+4x)-(y²-4y)