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    • 各位大侠求解一道题（-1x1/2)+（-1/2x1/3）......（-1/2006x1/2007）

    要用规律来接题的。。。【求解】

    举报该问题
    推荐答案   2011-09-24
    因为1/n×1/(n+1)=1/n-1/(n+1)
    则原式= -(1×1/2+1/2×1/3+........+1/2005×1/2006+1/2006×1/2007)
    = -(1-1/2+1/2-1/3+........+1/2005-1/2006+1/2006-1/2007)
    = -(1-1/2007)
    = -2006/2007
    温馨提示：答案为网友推荐，仅供参考
    其他回答
    第1个回答  2011-09-23
    -1*1/2=1/2 - 1 -1/2*1/3=1/3 - 1/2依次类推展开追问

    有没有用字母公式来解的，例如X N之类的

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