问题描述: 灰常难 六年级 1个回答 分类:数学 2019-10-30 问题解答: 我来补答 解法一: 1/3+1/6+1/12+1/24+1/48+1/96+1/192+1/384 =1/3+1/6+1/12+1/24+1/48+1/96+1/192+1/192-1/384 =1/3+1/6+1/12+1/24+1/48+1/96+1/96-1/384 =1/3+1/6+1/12+1/24+1/48+1/48-1/384 =1/3+1/6+1/12+1/24+1/24-1/384 =1/3+1/6+1/12+1/12-1/384 =1/3+1/6+1/6-1/384 =1/3+1/3-1/384 =2/3-1/384 =255/384 =85/128 解法二: 1/3+1/6+1/12+1/24+1/48+1/96+1/192+1/384 =1/3(1+1/2+1/4+1/8+1/16+1/32+1/64+1/128) =1/3(1-1/256)×2 =85/128 解法三: 1/3+1/6+1/12+1/24+1/48+1/96+1/192+1/384 =(384÷3+384÷6+384÷12+384÷24+384÷48+384÷96+384÷192+384÷384)/384 =(128+64+32+16+8+4+2+1)/384 =255/384 =85/128 展开全文阅读