设等差数列an中前n项和为sn,且s5=a5,若a4不等于0,则a7\a4=
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![设等差数列an中前n项和为sn,且s5=a5,若a4不等于0,则a7\a4=](/uploads/image/z/11964024-0-4.jpg?t=%E8%AE%BE%E7%AD%89%E5%B7%AE%E6%95%B0%E5%88%97an%E4%B8%AD%E5%89%8Dn%E9%A1%B9%E5%92%8C%E4%B8%BAsn%2C%E4%B8%94s5%3Da5%2C%E8%8B%A5a4%E4%B8%8D%E7%AD%89%E4%BA%8E0%2C%E5%88%99a7%5Ca4%3D)
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设等差数列an中前n项和为sn,且s5=a5,若a4不等于0,则a7\a4=
设等差数列an中前n项和为sn,且s5=a5,若a4不等于0,则a7\a4=
设等差数列an中前n项和为sn,且s5=a5,若a4不等于0,则a7\a4=
s5=a5,则a1+a2+a3+a4=0,则a1+a4=0,化简有2a1+3d=0.a7/a4=(a1+6d)/(a1+3d)=(2a1+12d)/(2a1+6d)=(9d)/(3d)=3.