Answer:
a + 4(n-1)
Step-by-step explanation:
The first term is a+4, the second term is a+8, the third term is a+12, etc.
A common theme that we can notice is that we add 4 for each term. For example, the second term (t₂) equals t₁+4, the third term equals t₂+4 (as a+4+4 = a+8), and so on. Another way of writing this is that we multiply 4 by (term number - 1) and add that to a. We can write this as
4 * (n-1) + a
