Explanation:
The given arithmetic sequence is of the form
a+d(n-1)
where 'a' is the first term and d is the common difference
In the case of
12+3(n-1)
we have a = 12 as our first term and d = 3 as the common difference. This means we start with 12 and add on 3 to each term to get the next one
12+3 = 15
15+3 = 18
18+3 = 21
21+3 = 24
and so on.
Side note: your teacher asks about the first four terms, but each answer choice lists five terms.
