2道简便运算,

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/06 03:44:00

2道简便运算,
2道简便运算,

2道简便运算,

=1+3+5+7+9+11+2/12+1/12+(3/60+2/60)+1/42

=36+3/12+1/12+1/42

=36+1/3+1/42=36+15/42

=(1/1-1/4)/3+(1/4-1/7)/3+(1/7-1/10)/3+...+(1/73-1/76)/3

=(1-1/4+1/4-1/7+1/7-1/10+.+1/73-1/76)/3

=(1-1/76)/3

=75/76/3

=25/76