4x(x2 - 3)=0
\(\left[{}\begin{matrix}x=0\\x^2-3=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=\pm\sqrt{3}\end{matrix}\right.\)
Lời giải .......................
\(4x^3-12x=0\)
\(\Leftrightarrow x\left(4x^2-12\right)=0\)
\(\Leftrightarrow x\left(2x-\sqrt{12}\right)\left(2x+\sqrt{12}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\2x-\sqrt{12}=0\\2x+\sqrt{12}=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{\sqrt{12}}{2}\\x=-\dfrac{\sqrt{12}}{2}\end{matrix}\right.\)
Vậy \(x=0\) ; \(x=\dfrac{\sqrt{12}}{2}\) hoặc \(x=-\dfrac{\sqrt{12}}{2}\)
4x3 - 12x = 0 => 4x(x2 -3) = 0
=> 4x = 0 hoặc x2 - 3 = 0
=> x = 0 hoặc x= căn 3 hoặc căn -3
