Question

What the nth term of 9,11,13,15,17​

Answer 1

`a_(n)` = 2n + 7

Explanation:

Note the differences between consecutive terms are constant, that is11 - 9 = 13 - 11 = 15 - 13 = 17 - 15 = 2 ← common difference

Thus the sequence is arithmetic with n th term

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = 9 and d = 2, thus

`a_(n)` = 9 + 2(n - 1) = 9 + 2n - 2 = 2n + 7

Answer 2

counting by 2 starting at three.

Explanation: