If the fraction cannot be simplified any more, you can multiply both the numerator and denominator by an number.
5/6 (multiply the top and bottom by 2) is the same as 10/12
8/22 (can be simplified by dividing top and bottom by 2) is 4/11
25/30 (simplified by dividing by 5) is 5/6
5/15 (simplified by dividing by 5) is 1/3
Hope this helps!