Find the greatest common factor (GCF) of 84 and 126.
Note
Prime-factor both numbers: 84 = 2^2 × 3 × 7 and 126 = 2 × 3^2 × 7; the GCF is the product of common primes with lowest powers: 2 × 3 × 7 = 42.
Find the greatest common factor (GCF) of 84 and 126.
Prime-factor both numbers: 84 = 2^2 × 3 × 7 and 126 = 2 × 3^2 × 7; the GCF is the product of common primes with lowest powers: 2 × 3 × 7 = 42.