What is the Greatest Common Factor of 9 and 20?
Greatest common factor (GCF) of 9 and 20 is 1.
GCF(9,20) = 1
We will now calculate the prime factors of 9 and 20, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 9 and 20.
How to find the GCF of 9 and 20?
We will first find the prime factorization of 9 and 20. After we will calculate the factors of 9 and 20 and find the biggest common factor number .
Step-1: Prime Factorization of 9
Prime factors of 9 are 3. Prime factorization of 9 in exponential form is:
9 = 32
Step-2: Prime Factorization of 20
Prime factors of 20 are 2, 5. Prime factorization of 20 in exponential form is:
20 = 22 × 51
Step-3: Factors of 9
List of positive integer factors of 9 that divides 9 without a remainder.
1, 3
Step-4: Factors of 20
List of positive integer factors of 20 that divides 9 without a remainder.
1, 2, 4, 5, 10
Final Step: Biggest Common Factor Number
We found the factors and prime factorization of 9 and 20. The biggest common factor number is the GCF number.
So the greatest common factor 9 and 20 is 1.
Also check out the Least Common Multiple of 9 and 20