Answer:18
Explanation:
Note: Mathematicians start counting at 1, so by convention, n=1 is the first term. So we must define what the first term is. Then we have to figure out and include the common difference.
Taking a look at the examples again,
Sequence: 1, 2, 3, 4, … | Formula: a(n) = n + 1 | Recursive formula: a(n) = a(n-1) + 1, a(1) = 1
Sequence: 3, 8, 13, 18, … |Formula: b(n) = 5n - 2 | Recursive formula: b(n) = b(n-1) + 5, b(1) = 3