1/4+1/28+1/70+.+1/9700=?

来源：学生作业学帮网编辑：学帮网时间：2024/06/04 09:00:13

1/4+1/28+1/70+.+1/9700
=1/3×(1-1/4+1/4-1/7+1/7-1/10+...+1/97-1/100)
=1/3×(1-1/100)
=1/3×99/100
=33/100

=1/1×4+1/4×7+……+1/97×100
=1-1/4+1/4-1/7+……+1/97-1/100
=1-1/100
=99/100