Question

Simplify the radical

Answer 1

$\sqrt[4]{81x^{20}y^{24}}\\\\Use\ (a^n)^m=a^{nm}\\\\=\sqrt[4]{3^4x^{5\cdot4}y^{6\cdot4}}=\sqrt[4]{3^4(x^5)^4(y^6)^4}\\\\Use\ \sqrt[n]{ab}=\sqrt[n]{a}\cdot\sqrt[n]{b}\\\\=\sqrt[4]{3^4}\cdot\sqrt[4]{(x^5)^4}\cdot\sqrt[4]{(y^6)^4}\\\\Use\ \sqrt[n]{a^n}=a\\\\=3|x^5|y^6\\\\Answer:\ \boxed{b.\ 3|x^5|y^6}\\\\Why\ |x^5|?\ Beacause\ \sqrt[4]{x^{20}}\geq0\to x^5\geq0\ if\ x\geq0\ and\ x^5$

Answer 2

I believe A should be the answer, hope that helps.