\(3x\left(x^2-4\right)=0\)
\(3x\left(x-2\right)\left(x+2\right)=0\)
\(\left[\begin{array}{nghiempt}x=0\\x-2=0\\x+2=0\end{array}\right.\)
\(\left[\begin{array}{nghiempt}x=0\\x=2\\x=-2\end{array}\right.\)
\(2x^2-x-6=0\)
\(2x^2-4x+3x-6=0\)
\(2x\left(x-2\right)+3\left(x-2\right)=0\)
\(\left(x-2\right)\left(2x+3\right)=0\)
\(\left[\begin{array}{nghiempt}x-2=0\\2x+3=0\end{array}\right.\)
\(\left[\begin{array}{nghiempt}x=2\\x=-\frac{3}{2}\end{array}\right.\)
1) \(3x(x^2-4)=0 \)
\(=> 3x(x-2)(x+2)=0\)
\(=>\left[\begin{array}{nghiempt}3x=0\\x-2=0\\x+2=0\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}x=0\\x=2\\x=-2\end{array}\right.\)
Vậy \(x\in\left\{0;2;-2\right\}\)
2) \(2x^2-x-6=0\)
\(2x^2-4x+3x-6=0\)
\(\left(2x^2-4x\right)+\left(3x-6\right)=0\)
\(2x\left(x-2\right)+3\left(x-2\right)=0\)
\(\left(x-2\right)\left(2x+3\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}x-2=0\\2x+3=0\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}x=2\\x=-\frac{3}{2}\end{array}\right.\)
Vậy \(x\in\left\{2;-\frac{3}{2}\right\}\)
a) \(3x\left(x^2-4\right)=0\)
\(\Rightarrow3x=0\) hoặc \(x^2-4=0\)
+) \(3x=0\Rightarrow x=0\)
+) \(x^2-4=0\Rightarrow x=2\) hoặc \(x=-2\)
Vậy \(x\in\left\{0;2;-2\right\}\)
1 3x(x2-4)=0
3x(x-2)2=0
3x(x-2)(x+2)=0
x=0 x=0
hoặc x-2= 0 => x=2
hoặc x+2=0 x=-2
Vậy x=0, x=2 , x=-2