
(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5+1/6)-(1/2+1/3+1/4+1/5+1/6)*(1/3+1/4+1/5)简便计算
4个回答
展开全部
(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5+1/6)-(1/2+1/3+1/4+1/5+1/6)*(1/3+1/4+1/5)
设1/2+1/3+1/4+1/5=a ,1/3+1/4+1/5=b
(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5+1/6)-(1/2+1/3+1/4+1/5+1/6)*(1/3+1/4+1/5)
=a*(b+1/6)-(a+1/6)*b
=(a-b)/6
=(1/2)/6=1/12
设1/2+1/3+1/4+1/5=a ,1/3+1/4+1/5=b
(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5+1/6)-(1/2+1/3+1/4+1/5+1/6)*(1/3+1/4+1/5)
=a*(b+1/6)-(a+1/6)*b
=(a-b)/6
=(1/2)/6=1/12
本回答被网友采纳
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
展开全部
令1/3+1/4+1/5=A
原式=(1/2 +A)(A+ 1/6)-(1/2 +A+ 1/6)·A
=A²+(1/2)A+(1/6)A+ 1/12 -A²-(1/2)A-(1/6)A
=1/12
原式=(1/2 +A)(A+ 1/6)-(1/2 +A+ 1/6)·A
=A²+(1/2)A+(1/6)A+ 1/12 -A²-(1/2)A-(1/6)A
=1/12
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
展开全部
(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5+1/6)-(1/2+1/3+1/4+1/5+1/6)*(1/3+1/4+1/5)
=(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5) + (1/6)*(1/2+1/3+1/4+1/5)
-(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5) -(1/6)*(1/2+1/3+1/4+1/5)
=0
=(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5) + (1/6)*(1/2+1/3+1/4+1/5)
-(1/2+1/3+1/4+1/5)*(1/3+1/4+1/5) -(1/6)*(1/2+1/3+1/4+1/5)
=0
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