Answer:
12.
Explanation:
We have been given format of different numbers. We are asked to find the missing value for our given format.

Taking square root of 9 and 16 we will get,



Similarly, we can see that by taking the square root of all the on the left side of equation and adding them we get right side of equation.






Upon taking square root of 25 and 49 we will get,



Therefore, the missing number of our given sequence is 12.