数学题,望大家解答.
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/10 10:04:31
数学题,望大家解答.
1+5+(1/2)+9+(1/6)+……+25+(1/42)
=(1+5+9+……+25)+[(1/2)+(1/6)+……+(1/42)]
=[(1+25)*7/2]+[1-(1/2)+(1/2)-(1/3)+……+(1/6)-(1/7)]
=91+1-(1/7)
=643/7
=(1+5+9+……+25)+[(1/2)+(1/6)+……+(1/42)]
=[(1+25)*7/2]+[1-(1/2)+(1/2)-(1/3)+……+(1/6)-(1/7)]
=91+1-(1/7)
=643/7