There are 4 positive and 4 negative numbers that go into 15.
They are: 1,3,5,15,-1,-3,-5, and -15.
The only number that can go into both numbers is 5
5
3 will go into both of these numbers
1 and 3 go into both.
1 and 7 will go into both the two given numbers
15, 25 and 75
These numbers: 1, 3, 5, 7, 15, 21, 35, 105.
1 and 2.
105, 210 and 315
1 and 3 will go into both numbers evenly
They have a common factor of 3.1, 2, 3, and 6 go into 6.1, 3, 5, and 15 go into 15.1 and 3 both go into 6 and 15.
9 and 11 both go into 99.