Respuesta :
Answer:
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
GCF = 3
Answer: 3
Step-by-step explanation: The factors of 30 are 1. 2. 3. 5. 6. 10, 15, 30
The factors of 42 are 1, 2, 3, 6, 7, 14, 21, 42
The factors of 45 are 1, 3, 5, 9, 15, 45
As you can see they all share the factors of 1 and 3. Since 3 is the greatest number of the factors all of them share it is the greatest common factor.