Question

Find the nth term of the sequence

15,12,9,6,...

Answer 1

Below

Explanation:

Each term is 3 less than the one before it...so common d = -3:

An = 15 + (n-1) d where d = common difference = -3...this simplifies to :

An = 18-3n

Answer 2

Answer: 15 - (n-1) * 3

Explanation:

nth term: 15 - (n-1) * 3

Just keep trying formulas until you find one that works :>