Just 1.
Their only common factor is ' 1 '.
It is: 1
1
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
28/45 is about as simple as it can get. The numerator and denominator haveno common factor except ' 1 '.
45 and 28 have no common factor. In other words, you can't simplify that.
The GCF is 1.
The GCF is 1.
The least common factor of any two or more positive integers is always 1