原式 = 1- 1/2 +1/2 - 1/3 + 1/3 - 1/4 +……+1/2013 - 1/2014
= 1 - 1/2014
= 2013/2014麻烦详细点这还不够详细？！1/(1*2) = 1 - 1/21/(2*3) = 1/2 - 1/31/(3*4) = 1/3 - 1/4……1/(2013*2014) = 1/2013 - 1/2014--------------------------全部加起来，中间都抵销了，只剩 1 - 1/2014