Answer:
GCF = 3
Step-by-step explanation:
Express the numbers as a product of their primes.
42 = 2 × 3 + 7
30 = 2 × 3 × 5
45 = 3 × 3 × 5
Identify the prime factors common to all 3 numbers.
common prime factor = 3 , thus
The answer of this question is 42
