What is the greatest common factor of 2 and 9?

Since 2 is a Prime number, either it is the greatest common factor or 1 is. Since 2 is not a factor of 9, the greatest common factor is 1.

Another way to determine the greatest common factor is to find all the factors of the numbers and compare them.

The factors of 2 are 1 and 2.

The factors of 9 are 1, 3, and 9.

The only common factor is 1. Therefore, the greatest common factor is 1.

The greatest common factor can also be calculated by identifying the common prime factors and multiplying them together.

The prime factor of 2 is 2.

The prime factors of 9 are 3 and 3.

There are no prime factors in common, so the numbers are relatively prime, meaning the greatest common factor is 1.

Summary of results:

The common factor is 1.

The greatest common factor is 1.

The numbers are relatively prime.
The GCF is 1.
The GCF is 1.