20x , 15

Since 20x,15 contain both numbers and variables, there are two steps to find the GCF (HCF). Find GCF for the numeric part then find GCF for the variable part.

Steps to find the GCF for 20x,15:

1. Find the GCF for the numerical part 20,15

2. Find the GCF for the variable part x1

3. Multiply the values together

Find the common factors for the numerical part:

20,15

The factors for 20 are all numbers between 1 and 20, which divide 20 evenly.

Check numbers between 1 and 20

Find the factor pairs of 20 where x⋅y=20.

xy12021045

List the factors for 20.

1,2,4,5,10,20

1,2,4,5,10,20

The factors for 15 are all numbers between 1 and 15, which divide 15 evenly.

Check numbers between 1 and 15

Find the factor pairs of 15 where x⋅y=15.

xy11535

List the factors for 15.

1,3,5,15

1,3,5,15

List all the factors for 20,15 to find the common factors.

20: 1,2,4,5,10,20

15: 1,3,5,15

The common factors for 20,15 are 1,5.

1,5

The numbers do not contain any common variable factors. The GCF (HCF) of the numerical factors 1,5 is 5.

5

Find the GCF 20x , 15