(2x+y)(2x-3y)+x(2x-3y) (b-a)的2次方+2a（b-a）-（a-b） -3a的n-1方+6a的n次方-12a的n+1方

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 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 [(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y) 因式分解3x^2(x-y)+6x(y-x) 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 化简:5(x-y)+2(x+y)-3(x-y) 3x(x-y)+2y(x-y) 计算 化简3(x-y)-7(x--y)+2(y-x) 因式分解:3x(x-y)+2y(y-x) (x-y)^3×（x-y)^2×(y-x)