Help dont understand

Use set builder notation to represent the following set: { -3, -2, -1, 0}

What are “like terms”? why can we only add like terms?

Asequence {an} is defined recursively, with a1 = 1, a2 = 2 and, for n > 2, an = an-1 an-2 . find the term a241. a) 0 b) 1 c) 2 d) 1 2