Question

Simplify
spuare root 84

Answer 1

will be a surd

Answer 2

First factor 84 as much as possible
\[ 84 = 4*21 = 2*2*3*7 \]
If we look at the square root we have
\[ \sqrt{84} = \sqrt{2*2*3*7} = \sqrt{2^2*3*7} = 2\sqrt{3*7} = 2\sqrt{21} \]