Answer :
[tex] \sqrt{ \frac{4}{225} }= \sqrt{ \frac{ 2^{2}}{ 15^{2} } }= \frac{2}{15} [/tex]
That's pretty easy, find the square root of 4 which is 2. Then find the square root of 225 which is 15. Replace 4 with 2 and 225 with 15