Answer:
-3n + 18
Explanation:
To find the nth term we calculate the jump between the first 2 terms as this is a linear sequence :
12 - 15 = -3
This will be the co-efficient of n .
And we calculate the 0th term :
15 -(-3) = 15 +3 = 18
So our answer will -3n + 18
Hope this helped and have a good day