简算题:1/2+1/6+1/12+1/20+1/30+1/42
问题描述:
简算题:1/2+1/6+1/12+1/20+1/30+1/42
答
(1-1/2)+(1/2-1/3)+……(1/6-1/7)=1-1/7=6/7
简算题:1/2+1/6+1/12+1/20+1/30+1/42
(1-1/2)+(1/2-1/3)+……(1/6-1/7)=1-1/7=6/7