First list the factors of 16:1,2,4,8,16. Start with the largest factor (16) and see if it is also a factor of 104 by dividing 104 by 16. When you do you get 6.5, so it is not a factor. So try 8, and when you do you get 13. So 8 is the largest factor of 16 and 104.
15
2
7
2
The Greatest Common Factor of 26 and 104 is 26.
Greatest common factor of 39 and 104 is 13.
Since 52 is a factor of 104, it is automatically the GCF.
The greatest common factor of 63 and 104 is 1.
The greatest common factor of 104 and 130 is 26.
The greatest common factor of 112 and 104 is 8.
Since 26 is a factor of 104, it is automatically the GCF.