计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2

（x^2+xy/x-y)/（xy/x-y)计算 计算:2xy/(x+y)².(x+y)/4y 计算：(xy-x²)×x-y/xy 计算：5xy^2-[3xy^2-(4xy^2-2x^2y)]+2x^2y-xy^2 计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2 计算：3xy[2xy-x（y-2）+x] 计算3xy[2xy-x(y-2)+x-1] 计算(-xy)(x+2x²y) 计算：[(x-y)^2-(x+y)^2]/(-4xy)= 计算xy^2(-xy)^2-3/2xy^3*4/3x^2y 计算（xy-y^2)÷x-y/xy x-y/xy-y^2计算 计算：3xy(x²y-xy²+xy)-xy²(2x-xy+2x） 计算:12xy^2/(x+y) * (x^2 - y^2)/4xy 计算-（x²y+3xy-4）+3（x²y-xy+2） 计算x²y³-2x(4xy³) 计算下面式子{x-y+[(4xy)/(x-y)]}{x-y-[(4xy)/(x-y)]} 化简计算:[x-y+4xy/(x-y)] * [x+y-4xy/(x+y)]