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C.
考慮所有滿足\(\cases{\displaystyle a_1+a_2+a_3+\ldots+a_{2020}=2021 \cr \frac{1}{a_1}+\frac{1}{a_2}+\frac{1}{a_3}+\ldots+\frac{1}{a_{2020}}=2021}\)的2020個正數\(a_1,a_2,a_3,\ldots,a_{2020}\),則對於\(i=1,2,\ldots,2020\),\(\displaystyle a_i+\frac{1}{a_i}\)最大值為   

R.
\(\displaystyle \frac{1}{7}=\frac{a_1}{9}+\frac{a_2}{9^2}+\frac{a_3}{9^3}+\ldots+\frac{a_n}{9^n}+\ldots\)且\(a_i\in \{\;0,1,2,3,4,5,6\}\;\),則\(a_{300}=\)   

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2020-5-12 16:06

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2020-5-12 16:06

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