Answer:
a₁₈ = 113
Step-by-step 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
[tex]a_{n}[/tex] = 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