\(a,\Leftrightarrow2x^2\left(x^2-4\right)=0\\ \Leftrightarrow2x^2\left(x-2\right)\left(x+2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\\x=-2\end{matrix}\right.\\ b,\Leftrightarrow\left(x+10\right)\left(\dfrac{2}{5}x-1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x+10=0\\\dfrac{2}{5}x=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-10\\x=\dfrac{5}{2}\end{matrix}\right.\)
a) \(2x^4-8x^2=0\)
\(2x^2\left(x^2-4\right)=0\)
⇔\(\left[{}\begin{matrix}2x^2=0\\x^2=4\end{matrix}\right.\)
⇔\(\left[{}\begin{matrix}x=0\\\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\end{matrix}\right.\)
Giúp em câu này vs ạ