You just need to list the factors of all 3 numbers, and see what numbers they have in common!
15: 1,3,5,15
18: 1,2,3,6,9,18
12: 1,2,3,4,6,12
so in all you can say that the common factors of 15,18,12 is: 1 and 3
The answer is C. if you need the work I can give it to you
Last one okay bye have a nice day
Jannelle could go 4,720 miles hope this helps
