Question

2) What is 18th term in this sequence: 45, 49, 53, 57,

Answer 1

a₁₈ = 113

Explanation:

There is a common difference d between consecutive terms

d = 49 - 45 = 53 - 49 = 57 - 53 = 4

This indicates 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 = 45 and d = 4, then

a₁₈ = 45 + (17 × 4) = 45 + 68 = 113