What is the greatest common factor of 45 54 and 63?

Answer 1

The GCF of 45 54 and 63 is: 9

First, the GCF can be no greater than the difference between the numbers, which is 9. If you try 9 as a factor of each number in the set, you see that it divides evenly into each, and so it is the GCF.

For another approach, you can write down the prime factorization of each number in the set:

45 = 3*3*5

54 = 2*3*3*3

63 = 3*3*7

The common factors in the prime factorizations are 3*3 = 9, so that's the GCF.

Answer 2

The GCF is 9.

Answer 3

It is: 9

Answer 4

9 is.

Answer 5

9