计算:1/1×3+1/3×5+1/5×7+…+1/2005×2007

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计算:1/1×3+1/3×5+1/5×7+…+1/2005×2007
计算:1/1×3+1/3×5+1/5×7+…+1/2005×2007

计算:1/1×3+1/3×5+1/5×7+…+1/2005×2007
1/1×3+1/3×5+1/5×7+…+1/2005×2007
=(1/2)×2/1×3+(1/2)×2/3×5+(1/2)×2/5×7+…+(1/2)×2/2005×2007
=(1/2)×(1-1/3)+(1/2)×(1/3-1/5)+(1/2)×(1/5-1/7)+…+(1/2)×(1/2005-1/2007)
=(1/2)×(1-1/3+1/3-1/5+1/5-1/7+…+1/2005-1/2007)
=(1/2)×(1-1/2007)
=(1/2)×(2006/2007)
=1003/2007

=1/2(1-1/3+1/3-1/5……+1/2005-1/2007)
=1/2 * 2006/2007
=1003/2007

1/1×3+1/3×5+1/5×7+…+1/2005×2007
=(1/2)×2/1×3+(1/2)×2/3×5+(1/2)×2/5×7+…+(1/2)×2/2005×2007
=(1/2)×(1-1/3)+(1/2)×(1/3-1/5)+(1/2)×(1/5-1/7)+…+(1/2)×(1/2005-1/2007)
=(1/2)×(1-1/3+1/3-1/5+1/5-1/...

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1/1×3+1/3×5+1/5×7+…+1/2005×2007
=(1/2)×2/1×3+(1/2)×2/3×5+(1/2)×2/5×7+…+(1/2)×2/2005×2007
=(1/2)×(1-1/3)+(1/2)×(1/3-1/5)+(1/2)×(1/5-1/7)+…+(1/2)×(1/2005-1/2007)
=(1/2)×(1-1/3+1/3-1/5+1/5-1/7+…+1/2005-1/2007)
=(1/2)×(1-1/2007)
=(1/2)×(2006/2007)
=1003/2007
=1/2(1-1/3+1/3-1/5……+1/2005-1/2007)
=1/2 * 2006/2007
=1003/2007

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