Answer:
42
Step-by-step explanation:
Find the prime factorization of 126
126 = 2 × 3 × 3 × 7
Find the prime factorization of 420
420 = 2 × 2 × 3 × 5 × 7
To find the GCF, multiply all the prime factors common to both numbers:
Therefore, GCF = 2 × 3 × 7
GCF = 42
