Write a rule for the nth term of the sequence 5, 2,-1, -4

Answer 1

There is a common difference of -3, so this is an arithmetic series.

a_n+1 = a_n - 3

If a₁ = 5, then

a_n = a₁ -3(n - 1)

a_n = 5 - 3(n - 1)