12, Find the prime factorization of 60
60 = 2 × 2 × 3 × 5
Find the prime factorization of 144
144 = 2 × 2 × 2 × 2 × 3 × 3
To find the gcf, multiply all the prime factors common to both numbers:
Therefore, GCF = 2 × 2 × 3