如题所述
第1个回答 2022-09-12
1/2+1/6+1/12+1/20+------+1/2950写错了吧?是不是2970
如果是则
=1/1*2+1/2*3+1/3*4+……+1/54*55
=(1-1/2)+(1/2-1/3)+……+(1/54-1/55)
中间抵消
=1-1/55
=54/55
如果是则
=1/1*2+1/2*3+1/3*4+……+1/54*55
=(1-1/2)+(1/2-1/3)+……+(1/54-1/55)
中间抵消
=1-1/55
=54/55
