(x+3y)(x^2+9y^2)(x-3y)帮帮忙,我很急,请在今天给我答复,O(∩_∩)O谢谢

x(x-y)2-(y-x)3 [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x 化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/(x+y)/x 计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x [(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y) 计算：x+2y/x-y+2x/y-x-3y/x-y 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2 计算(x-y)^7÷(y-x)^6+9-x-y)^3÷(x+y)^2 x^3y^2+6x^2y+9x 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) 2X(2X-3Y)-3Y(X+Y) (-2x y)^2-(3y-x)(-x-3y) （x+2y)^2-(x+y)(3x-y) 计算(x+y)(x+y)^2(-x-y)^3