There cannot be a greatest common factor of just one number. To be common there need to be at least two numbers. If you find all the factors of two or more numbers, and you find some factors are the same ("common"), then the largest of those common factors is the Greatest Common Factor.
The factors of 84 are 1,2,3,4,6,7,12,14,21,28,42 and 84. To find a greatest common factor, you need to compare them to another number's factors.
Since 21 is a factor of 84, it is automatically the GCF and all of its factors are common.
The GCF of 12 and 84 is 12Method: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 12 are 1, 2, 3, 4, 6, and 12.The factors of 84 are 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, and 84.The common factors are 1, 2, 3, 4, 6, and 12. Therefore, the greatest common factor is 12.Since 12 is a factor of 84, it is automatically the GCF.
The greatest common factor of the numbers 21 and 84 is 21.
The greatest common factor of both numers is 7
The GCF is 12.
Since 21 is a factor of 84, it is automatically the GCF.
The greatest common factor (or greatest common divisor) of 35 and 84 is 7.
The greatest common factor of 77 and 84 is 7.
The greatest common factor of 76 and 84 is 4.
The greatest common factor of 84 and 105 is 21.
The greatest common factor of 37 and 84 is 1.