Hi!
All of these can be represented as fractions:
1.) 4/12
2.) 15/27
3.) 12/18
4.) 9/72
Now, if they are supposed to be simplified...
1.) Divide 4 and 12 by 4, and you get 1/3
2.) Divide 15 and 27 by 3, and you get 5/9
3.) Divide 12 and 18 by 6, and you get 2/3
4.) Divide 9 and 72 by 9, and you get 1/8
Hope this helps! :D