What is the square root of 125/2?
Start by factoring 125.
You can already see here that you can bring 5 out.
You can rewrite this as:
We now need to rationalize this. We can do that by multiplying both the numerator and denominator by a radical that will eliminate the radical in the denominator. In this case, that radical is
You won't be able to simplify it any further. :)