Question

What is the general rule for the arithmetic sequence?

15, 12, 9, 6, …
A.
3n – 18
B.
6(3 – n)
C.
3n + 12
D.
18 – 3n

Answer 1

There are two ways to say the general rule. They both mean exactly
the same thing, and they both generate the same sequence:

1). Starting with 15, each new term is 3 less than the one before it.

2). The nth term of the sequence is [ 18 - 3n ] or [ 3 times (6 - n) ].

Answer 2

Ohh so it's just a pattern really?