21 , 8

Find the common factors for the numerical part:

21,8

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 8 are all numbers between 1 and 8, which divide 8 evenly.

Check numbers between 1 and 8

Find the factor pairs of 8 where x⋅y=8.

xy1824

List the factors for 8.

1,2,4,8

1,2,4,8

List all the factors for 21,8 to find the common factors.

21: 1,3,7,21

8: 1,2,4,8

The common factors for 21,8 are 1.

1

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

1

Find the GCF 21 , 8