Question

Tìm X biết

3x(x²-4)=02x²-x-6=0

 

Answer 1

\(3x\left(x^2-4\right)=0\)

\(3x\left(x-2\right)\left(x+2\right)=0\)

\(\left[\begin{array}{nghiempt}x=0\\x-2=0\\x+2=0\end{array}\right.\)

\(\left[\begin{array}{nghiempt}x=0\\x=2\\x=-2\end{array}\right.\)

\(2x^2-x-6=0\)

\(2x^2-4x+3x-6=0\)

\(2x\left(x-2\right)+3\left(x-2\right)=0\)

\(\left(x-2\right)\left(2x+3\right)=0\)

\(\left[\begin{array}{nghiempt}x-2=0\\2x+3=0\end{array}\right.\)

\(\left[\begin{array}{nghiempt}x=2\\x=-\frac{3}{2}\end{array}\right.\)

Answer 2

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 \(x\in\left\{2;-\frac{3}{2}\right\}\)

Answer 3

1.x=-2, x=0, x=2

2.x=-3/2, x=2

Answer 4

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 \(x\in\left\{0;2;-2\right\}\)

 

Answer 5

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