1/1*3+1/3*5+1/5+7+1/7*9+...+1/1*2010+1/1*2011?

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1/1*3+1/3*5+1/5+7+1/7*9+...+1/1*2010+1/1*2011?1/1*3+1/3*5+1/5+7+1/7*9+...+1/1*2010+1/1*2011?1/1*3+1/

1/1*3+1/3*5+1/5+7+1/7*9+...+1/1*2010+1/1*2011?
1/1*3+1/3*5+1/5+7+1/7*9+...+1/1*2010+1/1*2011?

1/1*3+1/3*5+1/5+7+1/7*9+...+1/1*2010+1/1*2011?
1/1*3+1/3*5+1/5+7+1/7*9+...+1/2009*2011
=(1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+……+1/2009-1/2011)÷2
=(1-1/2011)÷2
=2010/2011÷2
=1005/2011

1/1*3+1/3*5+1/5×7+1/7*9+...+1/2009*2011
=1/2×(1-1/3+1/3-1/5+……+1/2010-1/2011)
=1/2×2010/2011
=1005/2011