Respuesta :

The GCF is the greatest common factor.
Find the factors for 45, 90, and 75;
45: 1, 3, 5, 9, 15, 45
90: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90 
75: 1, 3, 5, 15, 25, 75
Now find the biggest factor they have in all, which is 15.
Hope this helps.