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计算:1/3+1/(3+5)+1/(3+5+7)+L+1/(3+5+7+L+21) L要找规律

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计算:1/3+1/(3+5)+1/(3+5+7)+L+1/(3+5+7+L+21) L要找规律
其实L可能不用求。
计算:1/3+1/(3+5)+1/(3+5+7)+L+1/(3+5+7+L+21) L要找规律
1/3+1/(3+5)+1/(3+5+7)+……+1/(3+5+7+……+21)
=1/3+1/8+1/15+……+1/120
=1/2×(1-1/3+1/2-1/4+1/3-1/5+……+1/10-1/12)
=1/2×(1+1/2-1/11-1/12)
=1/2×175/132
=175/264
再问: 望有更详细回答,一定会采纳!!!!!!!!!
再答: 1/3+1/(3+5)+1/(3+5+7)+……+1/(3+5+7+……+21) =1/3+1/8+1/15+……+1/120 =1/1×3+1/2×4+1/3×5+……+1/10×12 =1/2×(1-1/3+1/2-1/4+1/3-1/5+……+1/10-1/12) =1/2×(1+1/2-1/11-1/12) =1/2×175/132 =175/264 已经很详细了