零点流下眼泪
花朵
共回答了29个问题采纳率:89.7% 举报
1-1/2+1/3-1/4+……+1/1997-1/1998+1/1999
=(1+1/2+1/3+1/4+……+1/1997+1/1998+1/1999)-2(1/2+1/4+……+1/1998)
=(1+1/2+1/3+1/4+……+1/1997+1/1998+1/1999)-(1+1/2+……+1/999)
=1/1000+1/1001+……+1/1998+1/1999
所以1-1/2+1/3-1/4+……+1/1997-1/1998+1/1999=1/1000+1/1001+……+1/1998+1/1999
如果本题有什么不明白可以追问,
如果满意请点击“选为满意答案”
1年前
10