If the greatest common factor of two or more numbers is 1, then they are

relatively prime.

Greatest common factor (GCF) is a number that is greatest among the

common factors of the numbers.

List the factors of each number.

Factors of 7 : 1, 7

Factors of 28 : 1, 2, 4, 7, 14

Identify the greatest common factor.

The greatest common factor of 7 and 28 is 7.

Since the GCF is not 1, 7 and 28 are not relatively prime.

The greatest common factor of 7 and 28 is 7.

7 and 28 are not relatively prime.

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