数学大师快来1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90要规律求求啦

来源:学生作业帮助网 编辑:六六作业网 时间:2024/10/06 21:39:33
数学大师快来1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90要规律求求啦数学大师快来1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/

数学大师快来1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90要规律求求啦
数学大师快来
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
要规律
求求啦

数学大师快来1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90要规律求求啦
原式=1/(1*2)+1/(2*3)+1/(3*4).+1/(9*10)
=1-1/2+1/2-1/3+1/3.+1/9-1/10
=1-1/10
=9/10