Yes.
The GCF of any two odd numbers is always odd. The GCF of any two even numbers is always even. The GCF of an odd and an even number is always odd.
The GCF of two even numbers is always even.
No. For example, the GCF of 8 and 12 is 4. The GCF of 12 and 18 is 6. The Greatest Common Factor of two even numbers will always be even, but it will not always be 2.
No, their GCF is always odd.
The same as what? The GCF of two numbers will be the same; the GCF of 3 and 9 will always be 3. The GCF of 9 and 12 will also always be 3, but the GCF of 4 and 12 will always be 4.
No. The GCF of 4 and 8 is 4.
No. The GCF of 8 and 12 is 4.
Use the prime factorizations to determine the GCF. If the GCF is 1, the numbers are relatively prime. If the two numbers have no prime factors in common, they are relatively prime.
The GCF is always 1.
Yes
No
Not necessarily.