3/(6n-5)* [ 6(n+1)-5 ]裂项.

问题描述:

3/(6n-5)* [ 6(n+1)-5 ]裂项.

3/(6n-5)* [ 6(n+1)-5 ]
=3*1/6(1(6n-5)-1/ [ 6(n+1)-5 ]
=1/2*(1(6n-5)-1/ (6(n+1)-5)