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等差数列an,bn的前n项和分别为Sn,Tn,若Sn/Tn=5n+1/3n-1,则a3/b3的值是多少.
人气:440 ℃ 时间:2020-04-08 00:11:12
解答

a3/b3
=(2*a3)/(2*b3)
=(a1+a5)/(b1+b5)
=5(a1+a5)/2 / 5(b1+b5)/2
=S5/T5
=(5*5+1)/(5*3-1)
=26/14
=13/7
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