设 a = 1+1/3+1/5+1/7+1/9,则
原式
= (a-1/9)(a-1) - a(a-1-1/9)
= a²-10a/9 +1/9 -a²+10a/9
= 1/9
~ 满意请采纳,不清楚请追问.
--------------------
~ 梳理知识,帮助别人,愉悦自己.
~ “数理无限”团队欢迎你
~ http://zhidao.baidu.com/team/view/%CA%FD%C0%ED%CE%DE%CF%DE
设 a = 1+1/3+1/5+1/7+1/9,则
原式
= (a-1/9)(a-1) - a(a-1-1/9)
= a²-10a/9 +1/9 -a²+10a/9
= 1/9
~ 满意请采纳,不清楚请追问.
--------------------
~ 梳理知识,帮助别人,愉悦自己.
~ “数理无限”团队欢迎你
~ http://zhidao.baidu.com/team/view/%CA%FD%C0%ED%CE%DE%CF%DE