|1/20-1/19|+|1/19-1/18|+|1/18-1/17|+.+|1/2-1|

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/23 14:31:50
|1/20-1/19|+|1/19-1/18|+|1/18-1/17|+.+|1/2-1||1/20-1/19|+|1/19-1/18|+|1/18-1/17|+.+|1/2-1||1/20-1/19

|1/20-1/19|+|1/19-1/18|+|1/18-1/17|+.+|1/2-1|
|1/20-1/19|+|1/19-1/18|+|1/18-1/17|+.+|1/2-1|

|1/20-1/19|+|1/19-1/18|+|1/18-1/17|+.+|1/2-1|
=1/19-1/20+1/18-1/19+1/17-1/18+.1-1/2
=1-1/20
=19/20

|1/20-1/19|+|1/19-1/18|+|1/18-1/17|+......+|1/2-1|
=1/19-1/20+1/18-1/19+1/17-1/18+……+1-½
=-1/20+1
=19/20

|1/20-1/19|+|1/19-1/18|+|1/18-1/17|+......+|1/2-1|
=1/19-1/20+1/18-1/19+1/17-1/18+1/16-1/17+.....+1/2-1/3+1-1/2
=-1/20+1
=19/20

=1/19-1/20+1/18-1/19+1/17-1/18+..........+1-1/2= -1/20+1=19/20

1/20-1/19|+|1/19-1/18|+|1/18-1/17|+......+|1/2-1|
=1/19-1/20+1/18-1/19+1/17-1/18+……+1-½
=-1/20+1
=21/20

差为负值时,去掉绝对值符号后,减数与被减数互调位置
|1/20-1/19|+|1/19-1/18|+|1/18-1/17|+......+|1/2-1|
=1/19-1/20+1/18-1/19+1/17-1/18+1/16-1/17+.....+1/2-1/3+1-1/2
=-1/20+1
=19/20

19/20