6x^2-12xy+6y^2/3x-3y 谢谢帮帮忙,要理由!1快一点

1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) 因式分解 x-xy+3y-3x 2x+xy-y-4x+5y-6 (x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)答案应为-2x-x*x-3x， x^2-xy-6y^2+3xy+y+2 3y/x*x-y*y+x/x*x-2xy+y*y+6y*y/x*x*x-x*x*y-xy*y+y*y*y等于多少? 因式分解:12xy^2(y-x)+xy^3(x-y)+4x^2y(x-y) x^2+xy-6y^2-3x+6y 2x^2+3xy+y^2+x-y-6 x²+3xy+2y-x+y-6因式分解 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 5x^3y*(-3y)^2+(-6xy)^2*(-xy)+xy^3*(-4x^2) 化简分式方程:x*x-xy-y*y/x*x-3x-6y+2xy 因式分解：x(y-3)-(2y-6) (x+y)^3-(x-y)^2(x+y) x(x^2-xy)-(4x^2-4xy) 分解公因式分解 x(y-3)-(2y-6) 2.(x+y)^3-(x-y)^2(x+y) 3.x(x^2-xy)-(4x^2-4xy) 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 已知xy/x+y=6,求3x-2xy+3y/-x+3xy-y的值.