simplify this radical.\n$sqrt{84}$\n$2sqrt{21}$\n$2sqrt{42}$\n$4sqrt{21}$\n$4sqrt{42}$
simplify this radical.\n$sqrt{84}$\n$2sqrt{21}$\n$2sqrt{42}$\n$4sqrt{21}$\n$4sqrt{42}$
Answer
Explanation:
Step1: Factorize 84
$84 = 4\times21$
Step2: Apply square - root property
$\sqrt{84}=\sqrt{4\times21}$ Since $\sqrt{ab}=\sqrt{a}\times\sqrt{b}$ ($a = 4$, $b = 21$) and $\sqrt{4}=2$, we have $\sqrt{84}=\sqrt{4}\times\sqrt{21}=2\sqrt{21}$
Answer:
A. $2\sqrt{21}$