计算x(y-x)÷x^2-2xy+y^2\xy·x-y\x^2数学高手来

（x^2+xy/x-y)/（xy/x-y)计算 计算：(x+y/x-y)÷(xy+x^2) 计算（xy-y^2)÷x-y/xy x-y/xy-y^2计算 计算；（xy-x²）÷x²-2xy+y²/xy · x-y/x² （xy-x^2)乘以(xy)/(x-y) 计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2 (x^2-xy)y÷y-x/xy怎么做? 计算3xy[2xy-x(y-2)+x-1] 计算：3xy[2xy-x（y-2）+x] 数学化简计算:(x+y)^2/xy-(x-y)^2/xy x-y/x²÷x²-2xy+y²/xy*（xy-x²）