Answer:
5
Explanation:
Square Root - Finding a number that multiplies itself twice into the number within the square root
With this meaning, we need to find a number that multiplies itself into 625.
Finding calculations using exponents will help,
25^2 is equal to 625. Therefore

We are not finished, as there is another square root right after, empowering the parenthesis, so what number multiplies itself equals 25?
This would be 5, therefore
is equal to 5.