问题描述:1/2+1/6+1/12+1/20+1/30最佳答案: 解:1/2+1/6+1/12+1/20+1/30=1/(1x2)+1/(2x3)+1/(3x4)+1/(4x5)+1/(5x6)=(1-1/2) +(1/2-1/3)+……+(1/5-1/6)=1-1/6=5/6 ?? 点击显示答案