Factors are two numbers that can be multiplied to make the original number.

To find the greatest common factor, it helps to make a list of each set of factors and then compare both lists and find the largest number common to both. That will be the greatest common factor.

45

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1 x 45

3 x 15

5 x 9

Factors of 45: 1, 3, 5, 9, 15, 45

60

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1 x 60

2 x 30

3 x 20

4 x 15

5 x 12

6 x 10

Factors of 60: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60

Out of both lists, 15 is the largest number on each. That makes 15 the greatest common factor of 45 and 60.

1 x 45

3 x 15

5 x 9

Factors of 45=( 1,3,5,9,15,45)

1 x 60

2 x 30

3 x 20

4 x 15

5 x 12

6 x 10

Factors of 60=( 1,2,3,4,5,6,10,12,15,20,30,60)

Common Factors of 45 and 69 =( 1,2,3,5,15)

The greatest Common Factors of 45 and 69 =15

The greatest common factor of 45 and 60 is 15. The factors of 45 are 1, 3, 5, 9, 15, and 45. The factors of 60 are 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60. Fifteen is the largest number common to both sets.

...Factors of 45={ 1,3,5,9,15,45}

Factors of 60={ 1,2,3,4,5,6,10,12,15,20,30,60}

Common Factors of 45 and 69 ={ 1,2,3,5,15}

The greatest Common Factors of 45 and 69 =15

45 and 60?

3 45 60

5 15 20

3 4

since 3 and 5 are numbers that divides both 45 and 60 without leaving a remainder.

Greatest common factor = 3*5= 15

The highest common factor that divides into both 45 and 60 is the number 15. It divides into 45 three times, and in to 60, four times.

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