x(y-x)÷x^2-2xy+y^2\xy·x-y\x^2数学高手来

（xy-x^2)乘以(xy)/(x-y) （x^2+xy/x-y)/（xy/x-y)计算 (x^2-xy)y÷y-x/xy怎么做? x-y/x²÷x²-2xy+y²/xy*（xy-x²） 计算：(x+y/x-y)÷(xy+x^2) 因式分解：x×x-xy-2y×y-x-y 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) 作乘法:(x+y)(x^2-xy+y^2)；(x-y)(x^2+xy+y^2) (x+y-2xy)(x+y-2)+(1-xy)² (x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y) x根号x+x根号y/xy-y^2)-（x+根号xy+y/x根号x-y根号）y 计算；（xy-x²）÷x²-2xy+y²/xy · x-y/x²