21 , 6

Find the common factors for the numerical part:

21,6

The factors for 21 are all numbers between 1 and 21, which divide 21 evenly.

Check numbers between 1 and 21

Find the factor pairs of 21 where x⋅y=21.

xy12137

List the factors for 21.

1,3,7,21

1,3,7,21

The factors for 6 are all numbers between 1 and 6, which divide 6 evenly.

Check numbers between 1 and 6

Find the factor pairs of 6 where x⋅y=6.

xy1623

List the factors for 6.

1,2,3,6

1,2,3,6

List all the factors for 21,6 to find the common factors.

21: 1,3,7,21

6: 1,2,3,6

The common factors for 21,6 are 1,3.

1,3

The GCF (HCF) of the numerical factors 1,3 is 3.

3

Find the GCF 21 , 6