Answer:
a)

b)

Explanation:
This is just an arithmetic sequence. The generic form of an arithmetic sequence is:
, where
is the first term of the sequence and d is the common difference.
a) Here, we can see that the common difference is 3 (because 5 - 2 = 3, 8 - 5 = 3, etc). So, d = 3. Also, the first term is 2, so a_1 = 2. Now, we can just write our expression:


b) Here, the common difference is 2 (since 11 - 9 = 2, 13 - 11 = 2, etc). So, d = 2. Also, the first term is 9, so a_1 = 9. Now our expression is:


Hope this helps!