(1+1/2)(1+1/4)(1+1/6).(1+1/20)(1-1/3)(1-1/5)+(1-1/7).(1-1/2

来源：学生作业帮助网编辑：六六作业网时间：2024/05/16 16:50:33

(1+1/2)*(1+1/4)*(1+1/6)*.*(1+1/20)*(1-1/3)*(1-1/5)+(1-1/7)*.*(1-1/2(1+1/2)*(1+1/4)*(1+1/6)*.*(1+1/20

(1+1/2)*(1+1/4)*(1+1/6)*.*(1+1/20)*(1-1/3)*(1-1/5)+(1-1/7)*.*(1-1/2
(1+1/2)*(1+1/4)*(1+1/6)*.*(1+1/20)*(1-1/3)*(1-1/5)+(1-1/7)*.*(1-1/2

(1+1/2)*(1+1/4)*(1+1/6)*.*(1+1/20)*(1-1/3)*(1-1/5)+(1-1/7)*.*(1-1/2
(1+1/2)*(1+1/4)*(1+1/6)*.*(1+1/20)*(1-1/3)*(1-1/5)+(1-1/7)*.*(1-1/21)
=(3/2)(5/4)(7/6)...(21/20)(2/3)(4/5)(6/7)...(20/21)
=(3/2)(2/3)(5/4)(4/5)...(21/20)(20/21)
=1