Hello!
In this question, you are finding the square root of 100-84.
The first thing you should do is do whatever is inside the square root sign. So, do 100-84:
100-84= 16
Now, you can take the square root of that number. Taking the square root means which number, when multiplied by itself, equal the number under the square root sign? In this case, the answer is 4!
This is because 4 multiplied by itself ( 4 times 4) is 16!
Answer: 4
I hope this helped! Comment if you have questions!