(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)答案应为-2x-x*x-3x，

x^2-xy/xy-y^2约分 2x²y-3(2xy-xy)-xy （x^2+xy/x-y)/（xy/x-y)计算 (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-y)(x^2+xy+y^2) 化简x^-y^/x^-2xy+y^ 2*(x-y)²(y-x)(xy) ((xy+2)(xy-2)-2x²y²+5(xy-y)²)÷(2xy) （y/(x^2-xy)+x/(y^2-xy))除以(x-y)/(xy) x^2-xy-6y^2+3xy+y+2 计算（xy-y^2)÷x-y/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 计算：x²+2xy+y²/xy-y².x²-2xy+y²/xy+y² xy-2{xy-[3x^2y-(4xy^2+0.5xy)]+4x^2y}+6xy^2 （X-3xy+4xy-y）-[-2x-2（xy-3/2xy）-y]+6xy的过程 x^2y-2xy+y化简