Question

\(\sqrt{\sqrt{81}}=\sqrt[4]{x}\)

Tìm x

Answer 1

\(\sqrt{81^{\frac{1}{2}}}=\sqrt[4]{x}\)<=> \(81^{\frac{1}{4}}=x^{\frac{1}{4}}\)

Answer 2

\(\sqrt{\sqrt{81}}=\sqrt[4]{x}\)

\(\Rightarrow81=\sqrt{x}\)(Bình phương 2 vế)

\(\Rightarrow x=9\)