Answer:
nth term = 18 - 3n
Step-by-step explanation:
nth term = a + (n - 1)d
a1 = 15
d = -3
nth term = a + (n - 1)d
= 15 + (n - 1)-3
= 15 + (-3n + 3)
= 15 - 3n + 3
= 18 - 3n
nth term = 18 - 3n
For instance, if you want to find the 10th term
nth term = 18 - 3n
10th term = 18 - 3(10)
= 18 - 30
= -12
10th term = -12