Question

\(\sqrt[3]{x^2 +2}=3\\ \)

Answer 1

\(\sqrt[3]{x^2+2}=3\)

\(\Leftrightarrow x^2+2=27\Leftrightarrow x^2=25\)

\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=-5\end{matrix}\right.\)

Answer 2

\(^3\sqrt{x^2+2}=3\)

\(\left(^3\sqrt{x^2+2}\right)^3=3^3\)

\(x^2+2=27\)

\(x^2=25\)

⇒\(\left[{}\begin{matrix}x=5\\x=-5\end{matrix}\right.\)

Answer 3

\(\sqrt[3]{x^2+2}=3\\ \Rightarrow x^2+2=27\\ \Rightarrow x^2=25\\ \Rightarrow\left[{}\begin{matrix}x=-5\\x=5\end{matrix}\right.\)