Write a formula for the general term​ (the nth​ term) of the arithmetic sequence

Question

Write a formula for the general term​ (the nth​ term) of the arithmetic sequence below. Then use the formula for

a_n to find a₂₀​, the 20th term of the sequence.

2,5,8,11...

Answer 1

2,5,8,11,14,17,20,23,26,29,32,35,38,41,44,47,50,53,56,59,62,65,68,71,74,77,80,....

f(n) = 2 + 3 (n-1)

= 2 + 3n-3

= 3n-1

f(1) = 2

f(20) = 3(20)-1 = 60-1 = 59