2道题目的方法是一样的1/2=1 -1/21/6=1/2-1/31/12=1/3-1/4……1/2-1/6-1/12-1/20-1/30-1/42 =1-1/2+1/2-1/3+1/3-1/4+……+1/6-1/7=1-1/7=6/7第二题=1-1/2+1/2-1/3+1/3-1/4+……+1/2004-1/2004 =1-1/2004=2003/2004...