(xy-x^2)/(x-y)/xy 第一个是除号,第二个是分数

x^2-xy/xy-y^2约分 第一题：(3xy^2)^2+(-xy^3)×(-4xy) 第二题：（2x^3y)2×（-2xy)+(-2x^3y)^3×(2x)^2 （x^2+xy/x-y)/（xy/x-y)计算 2x²y-3(2xy-xy)-xy 【x(xy-xy)-y(x-xy)】÷3xy (x^2+2xy+y^2-4xy)*(x^2-2xy+y^2+4xy) .(x+y-2)(x+y-2xy)+(xy-1)^2 (x^2-xy)y÷y-x/xy怎么做? |x|/x+y/|y|+xy/|xy|= (xy-x²)÷(x²-2xy+y²/xy)×（x-y/x²） x-y/x²÷x²-2xy+y²/xy*（xy-x²） （y/(x^2-xy)+x/(y^2-xy))除以(x-y)/(xy) (-x-y)(x^2+xy+y^2) 化简x^-y^/x^-2xy+y^ 2*(x-y)²(y-x)(xy) 初二数学化简分式x^2 -y^2/xy - xy-y^2/xy-x^2x^2 -y^2/xy - xy-y^2/xy-x^2 3xy(x^2y-xy^2+xy)-xy^2(2x^2-6xy+2x)过程 ((xy+2)(xy-2)-2x²y²+5(xy-y)²)÷(2xy)