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(-1/2)-(-1/3)-(+1/4)

来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/11 11:32:09
(-1/2)-(-1/3)-(+1/4)
(-1/2)-(-1/3)-(+1/4)
(-1×1/2)+(-1/2×1/3)+(-1/3×1/4)+……+(-1/2004×1/2005)
=-1/(1×2)+[-1/(2×3)]+[-1/(3×4)]+……+[-1/(2004×2005)]
=-(1/1-1/2)+[-(1/2-1/3)]+[-(1/3-1/4)]+……+[-(1/2004-1/2005)]
=-1+1/2-1/2+1/3-1/3+1/4-……-1/2004+1/2005
=-1+1/2005
=-2004/2005