Question

simplify this radical.\\(sqrt{84}\\)\\(4sqrt{21}\\)\\(2sqrt{21}\\)\\(2sqrt{42}\\)\\(4sqrt{42}\\)

Explanation:

Step1: Factor out perfect square

$\sqrt{84} = \sqrt{4 \times 21}$

Step2: Split the radical

$\sqrt{4 \times 21} = \sqrt{4} \times \sqrt{21}$

Step3: Simplify perfect square root

$\sqrt{4} \times \sqrt{21} = 2\sqrt{21}$

Answer:

$2\sqrt{21}$