it can be in the way of squaring a number for example is 5
5^2 is equal to 25
the sqrt of 25 is 5 because 5*5 is 25
or any number that are perfect square
while if the given is not in the perfect square so it will remain you will not remove the sqrt sign for example is sqrt of 15 that is not a perfect square therefore you will not remove the sqrt sign
hope it will help ^_^
