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The common factors of 21 and 42 are 3, 7 and 21. The greatest common factor (GCF) is 21.

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Q: What are the common factors and greatest common factor of 21 and 42?

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The factors of 14 and 21 are: 14: 1,2,7,14 21:1,3,7,21 The common factors are:1 and 7. Therefore 7 is the greatest common factor (GCF)

The greatest common factor of 21 and 99 is 3. 21's factors are 1,3,and 7 99's factors are 1,3,9,11 33 (there may be more factors of 99). The highest factor that both number have in common are 3.

The GCF of 21 and 45 is 3. One way to determine the greatest common factor is to find all the factors of the numbers and compare them. The factors of 21 are 1, 3, 7, and 21. The factors of 45 are 1, 3, 5, 9, 15, and 45. The common factors are 1 and 3. Therefore, the greatest common factor is 3. The greatest common factor can also be calculated by identifying the common prime factors and multiplying them together. The prime factors of 21 are 3 and 7. The prime factors of 45 are 3, 3, and 5. The prime factors in common are a single 3, so the greatest common factor is 3.

The GCF of 21 and 25 is 1Definition: A factor is a divisor - a number that will evenly divide into another number. The greatest common factor of two or more numbers is the largest factor that the numbers have in common.Method:One way to determine the common factors and greatest common factor is to find all the factors of the numbers and compare them.The factors of 21 are 1, 3, 7, and 21.The factors of 25 are 1, 5, and 25.The only common factor is 1. Therefore, the greatest common factor is 1, which means the numbers are relatively prime.The greatest common factor of 21 and 25, is 1.The factors of 21 are: 1, 3, 7, 21The factors of 25 are: 1, 5, 25The common factors are: 1The GCF is 1.

The GCF of 4 and 21 is 1.A factor is a divisor - a number that will evenly divide into another number. The greatest common factor of two or more numbers is the largest factor that both numbers have in common.One way to determine the common factors and greatest common factor is to find all the factors of the numbers and compare them.The factors of 4 are 1, 2, and 4.The factors of 21 are 1, 3, 7, and 21.The only common factor is 1. Therefore, the greatest common factor is 1.The GCF is 1.

Related questions

The greatest common factor is 3

There is neither a greatest common factor nor common factors of a single number, such as 21, because there cannot be any form of common factor without two or more numbers to compare. Common factors are factors that the numbers being compared have in common. The greatest common factor is the largest factor that all the numbers being compared have in common. Thus, since there are not two or more numbers to compare, there are neither common factors nor a greatest common factor. The factors of 21 are 1, 3, 7, and 21.

The greatest common factor of 21 and 40 is 1 because there are no larger common factors.

Since 21 is a factor of 84, it is automatically the GCF and all of its factors are common.

The factors of 14 are: 1, 2, 7, 14.The factors of 21 are: 1, 3, 7, 21.The Greatest Common Factor (GCF) is: 7.

The Greatest Common Factor (GCF) is: 3

The Greatest Common Factor (GCF) is: 1

The Greatest Common Factor (GCF) is: 7

The Greatest Common Factor (GCF) is: 7

The greatest common factor of 63 and 147 is 21.

The greatest common factor of 15 and 21 is 3The factors of 15 are: 1, 3, 5, 15The factors of 21 are: 1, 3, 7, 21The common factors are: 1, 3The Greatest Common Factor (GCF) is: 3

Common Factors: 2, 7 Greatest Common Factor: 7 * * * * * 2 is NOT a factor of 21 and so it cannot be a common factor.