The expressions for the sum to n terms of some arithmetic sequences are given below. Find the expression for the nth term of each:
n2 – 2n
Sn = n2 – 2n
an + 1 = Sn + 1-Sn
= {(n + 1)2-2(n + 1)}- (n2 – 2n)
= n2 + 2n + 1-2n-2-n2 + 2n
= 2n-1
= 2(n + 1)-3
an = 2n-3
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