Well, if you ignore that it's a fraction, then it becomes so much easier... all you do is square root 16 which is 4, then put it back into the fraction and you have 1/4 :) Check it on your calculator if you like, it works. Hope I helped x
You square root 16 to get 4. (you first do the bottom, as it makes it easier)
And the fact that there is a minus sign on the indice it cancels out with the fraction you have. So it wouldn't be 1/4..it would be 4.
Hope i helped, sorry im not very good at explaining.
Good luck for tomorrow (: