X mũ 4 bằng 16 làm như thế nào

$x^{4}=16$

⇔ \(\left[ \begin{array}{l}16=2^{4}\\16=(-2)^{4}\end{array} \right.\) 

$⇒ x^{4} =$ \(\left[ \begin{array}{l}2^{4}\\(-2)^{4}\end{array} \right.\) 

$⇒$ \(\left[ \begin{array}{l}x=2\\x=-2\end{array} \right.\)