You want to know whether the numerator (the first term) and the denominator (the second) can be divided by the same number.
Generally, if something has 5 at the end, we can divide it by 5, so that means we can divide it by 5, let's try:
25/5=5
75/5=15.
so then we have 5/15.
we can divide again:
5/5=1
15/5=3
So the final answer is 1/3.