110 is a composite number, so, begin by makin a factor tree. Place 110 at the top, draw two arrows in a downward direction with 2 and 55 at the end of each. Since 2 is a prime number, move on to 55, which is also composite. Make two more downward arrows and place 5 and 11 at the ends. So, your prime factorization is 110=2*5*11.