Question 674933
First of all, the number of which you are trying to get the square root must contain at least one perfect square as a factor. Secondly, you can not "simplify" the square root of a prime number. You want 
(1)  x = {{{sqrt(117)}}}
So we must be able to factor 117
(2) 117 = 3*39 or
(3) 117 = 3*3*13 or
(4) 117 = (3^2)*(13)
Then (1) becomes
(5) x = {{{sqrt((3^2)*(13))}}}
Now use the very useful identity
(6) {{{sqrt(a*b)}}} = {{{sqrt(a)}}}*{{{sqrt(b)}}}
Then (5) becomes your answer
(7) x = 3*{{{sqrt(13)}}}