To find out the GCF of two numbers, you first split them into their prime factors:
57 = 3x19
27 = 3x3x3
The next step is to identify any common factors. In this case, both numbers have a single 3 as a prime factor. Thus, the greatest common factor of 57 and 27 is 3.
The GCF of 27 and 57 is 3
27 = 3 x 3 x 3; 57 = 3 x 19: GCF = 3
The GCF is 3.
The GCF is 3.
The GCF is 3.
The GCF is 28.
The GCF is 3.
The GCF is 3.
The GCF is 3.
The GCF is 3.
The GCF is 1.
The GCF is 1.