To use the distributive property, we "distribute" a value on the outside of a set of parentheses to all of the values on the inside of the parentheses. For example...
6(3 + 9) = 6*3 + 6*9
For your problem, you only have one value 13.99, but we can split it apart to make it a little easier to work with (like with mental math). We can say that 13.99 is the same as 10 + 3.99. Now we can take it and multiply by 9 with the distributive property...
If you cross multiply so you times the denominators together to get 15 and then times 4 by 3 and 2 by 5 to get the numerators so the question would be: 12/15-10/15 = 2/15