The expressions for the sum to n terms of some arithmetic sequences are given below. Find the expression for the nth term of each:
2n2 – n
Sn = 2n2 - n
an + 1 = Sn + 1 - Sn
= {2(n + 1)2-(n + 1)}- {2n2 - n}
= (2n2 + 4n + 2-n-1)-(2n2-n)
= 4n + 1
= 4(n + 1)-3
an = 4n-3
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