
Step-by-step explanation
An arithmetic sequence is an ordered set of numbers that have a common difference between each consecutive term,it is give by the expression:

so
Step 1
use the given data to find the arithmetic sequence
so
let

so
a) find the common difference

hence the common difference is 3

now, chec the first term and replace in the formula

Step 2
now, use the expression to find teh netx two terms
a)

b) fifth term

so, the answer is

I hope this helps you