高分求解(2x+3y)(a-b)-2(a-b)(x+y) (a+b/3)(a平方-1/3ab+1/9b平方) 2x(2x-y)平方-y(y-2x)平方

请再给我一点问题补充

(2x+3y)(a-b)-2(a-b)(x+y) = (a-b)[2x + 3y - 2x - 2y]
= (a-b)y

(a+b/3)(a^2-1/3ab+1/9b^2) = a^3 + (b/3)^3 = a^3 + b^3/27

2x(2x-y)^2 - y(y-2x)^2 = (2x-y)^2[2x-y] = (2x - y)^3

1.
(2x+3y)(a-b)-2(a-b)(x+y)
=(a-b)[(2x+3y)-2(x+y)]
=(a-b)[2x+3y-2x-2y]
=(a-b)(y)
=y(a-b);

2.
(a+b/3)(a^2-ab/3+b^2/9)
=(a+b/3)(a-b/3)^2

3.
2x(2x-y)^2-y(y-2x)^2
=2x(2x-y)^2-y(2x-y)^2
=(2x-y)^2(2x-y)
=(2x-y)^3.

三道题吧？

(2x+3y)(a-b)-2(a-b)(x+y) = (a-b)(2x + 3y - 2x - 2y) = (a-b)y

(a+b/3)(a^2-1/3ab+1/9b^2) = a^3 + (b/3)^3 = a^3 + b^3/27

2x(2x-y)^2 - y(y-2x)^2 = (2x-y)^2(2x-y) = (2x - y)^3

楼主检查下题目可否正确，我尝试多种方法，仍无法找出规律，只能越算越复杂！

lz：提有点乱阿
不好意思， 说实话看不懂