Question

pls answer really quick useless answers will be reported​

Answer 1

Answer:

5

Step-by-step explanation:

You need to start from the inner root ie $\sqrt{225} =15$

So that would simply it to,

                                     $\sqrt{21+15} =\sqrt{36}$

Again simplifying,

                                     $\sqrt{19+6}=\sqrt{25}$

                                                  $=5$