（2b）的3次方
1个回答
展开全部
(a + 2b + c)^3 - (a + b)^3 - (b + c)^3
= (a + 2b + c)^3 - [(a + b)^3 + (b + c)^3]
=(a +2b+ c)^3-[(a+ b)+(b + c)][(a+b)^2+(b+c)^2-(a+b)(b + c)]
= (a + 2b + c)[3 b^2 + 3ab + 3ac + 3bc)
= 3 (a + b) (b + c) (a + 2 b + c)
= (a + 2b + c)^3 - [(a + b)^3 + (b + c)^3]
=(a +2b+ c)^3-[(a+ b)+(b + c)][(a+b)^2+(b+c)^2-(a+b)(b + c)]
= (a + 2b + c)[3 b^2 + 3ab + 3ac + 3bc)
= 3 (a + b) (b + c) (a + 2 b + c)
本回答被提问者采纳
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
