2个等差数列{An}、{Bn}的前n项和之比为5n+3/2n-1.则A10/B10=多少?
详细解答
人气:422 ℃ 时间:2020-05-20 11:33:45
解答
设5n+3/2n-1=t
则前10项和比为53/19
前9项和比为48/17
A10/B10=(53t-48t)/(19t-17t)=5/2
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