What is the Greatest Common Factor of 42 and 18?
Greatest common factor (GCF) of 42 and 18 is 6.
GCF(42,18) = 6
We will now calculate the prime factors of 42 and 18, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 42 and 18.
How to find the GCF of 42 and 18?
We will first find the prime factorization of 42 and 18. After we will calculate the factors of 42 and 18 and find the biggest common factor number .
Step-1: Prime Factorization of 42
Prime factors of 42 are 2, 3, 7. Prime factorization of 42 in exponential form is:
42 = 21 × 31 × 71
Step-2: Prime Factorization of 18
Prime factors of 18 are 2, 3. Prime factorization of 18 in exponential form is:
18 = 21 × 32
Step-3: Factors of 42
List of positive integer factors of 42 that divides 42 without a remainder.
1, 2, 3, 6, 7, 14, 21
Step-4: Factors of 18
List of positive integer factors of 18 that divides 42 without a remainder.
1, 2, 3, 6, 9
Final Step: Biggest Common Factor Number
We found the factors and prime factorization of 42 and 18. The biggest common factor number is the GCF number.
So the greatest common factor 42 and 18 is 6.
Also check out the Least Common Multiple of 42 and 18