1/1*5+1/5*9+1/9*13+.+1/55*59

问题描述:

1/1*5+1/5*9+1/9*13+.+1/55*59

1/1*5+1/5*9+1/9*13+.+1/55*59
=(1-1/5+1/5-1/9+1/9-1/13+……+1/55-1/59)÷4
=(1-1/59)÷4
=58/59÷4
=29/118