Question

Find a formula for the nth term in this

arithmetic sequence:
a1 = 9, a2 = 13, a3 = 17, 24 = 21, ...

PLS help

Answer 1

`a_(n)` = 4n + 5

Explanation:

The n th term of an arithmetic sequence is

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = 9 and d = a₂ - a₁ = 13 - 9 = 4 , thus

`a_(n)` = 9 + 4(n - 1) = 9 + 4n - 4 = 4n + 5