Question

Find a formula for an arithmetic sequence that begins 80, 83, 86, 89, ...​

Answer 1

`a_(n)` = 3n + 77

Explanation:

The nth 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 = 80 and d = a₂ - a₁ = 83 - 80 = 3 , then

`a_(n)` = 80 + 3(n - 1) = 80 + 3n - 3 = 3n + 77