Answer:
[tex]A_{n}[/tex] = 10n + 10
Step-by-step explanation:
There is a common difference between consecutive terms in the sequence
d = 30 - 20 = 40 - 30 = 10
This indicates the sequence is arithmetic with explicit formula
[tex]A_{n}[/tex] = a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = 20 and d = 10, thus
[tex]A_{n}[/tex] = 10 + 10(n - 1) = 10 + 10n - 10 = 10n + 10
