化简:[(x+y)²-(x-y)²]÷2xy
化简:[(x+y)²-(x-y)²]÷2xy
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
1.化简:x²-4y²/x²+y²+2xy÷2y+x/x²+xy.
化简x-y分之x + x³-2x²y+xy²分之y³ ÷ y²-x
化简(x²y-4y²)/(x²+4xy+4y²)*[(4xy)/(x-2y)+x
急![(3x+y)²-3(3x-y)(x+y)-(x-3y)(x+3y)]÷(2xy)
【(1)/(x-y)+(1)/(x-y)】÷(2x)/(x²-2xy+y²)
化简2XY+(X-Y)²
x²/xy-x/y
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
2x(x²y-xy²)+xy(xy-x²)]÷x²y等于多少
计算;(xy-x²)÷x²-2xy+y²/xy · x-y/x²