Final answer:
The nth term of an arithmetic sequence is generally represented by an equation involving the first term and the common difference. The examples provided don't fit the standard form without clarification on the first term and the common difference.
Step-by-step explanation:
The question is about finding the equation for the nth term of an arithmetic sequence. In the standard form of an arithmetic sequence, the nth term is given by an = a1 + (d)(n - 1), where a1 is the first term and d is the common difference between terms. The options provided in the question appear to be expressions, but without further context, it's difficult to determine which is an arithmetic sequence without the respective first term and common difference being clarified. However, the general method for deriving an nth term in an arithmetic sequence would not match the examples provided without additional operations or adjustments.