令S=2^0+2^1+2^2+……+2^(n-1) ①
那么2S=2^1+2^2+...+2^n②
①-②得到
(1-2)S=1-2^n
所以S=(1-2^n)/(1-2)
求证2^0+2^1+2^2+……+2^(n-1)=(1-2^n)/(1-2)
1个回答
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