\(a,\Leftrightarrow\dfrac{2}{3}x\left(x-2\right)\left(x+2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\\x=-2\end{matrix}\right.\\ b,\Leftrightarrow x\left(2x^2+2\sqrt{2}x+1\right)=0\\ \Leftrightarrow x\left(x\sqrt{2}+1\right)^2=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{1}{\sqrt{2}}\left(=-\dfrac{\sqrt{2}}{2}\right)\end{matrix}\right.\)
Trong ngoặc là nếu bạn muốn trục căn thức nhé

