Given that the sum of the first n terms of the sequence {an} is Sn, and Sn = n-5an-85, n ∈ n *, it is proved that {an-1} is an equal ratio sequence

Given that the sum of the first n terms of the sequence {an} is Sn, and Sn = n-5an-85, n ∈ n *, it is proved that {an-1} is an equal ratio sequence

∵ Sn = n-5an-85 ∵ an = SN-S (n-1) = n-5an-85 - (n-1) + 5A (n-1) + 85 = 1-5an + 5A (n-1) ∵ 6An = 5A (n-1) + 16an-6 = 5A (n-1) + 1-66 (an-1) = 5 (a (n-1) - 1) ∵ an-1 = 5 / 6 * (a (n-1) - 1) = 5 / 6 * B (n-1) ∵ {an-1} is an equal ratio sequence with a common ratio of 5 / 6,