\(x^3-4x=0\)
\(\Leftrightarrow x\left(x^2-4\right)=0\)
\(\Leftrightarrow x\left(x-2\right)\left(x+2\right)=0\)
\(\Leftrightarrow x=0hoacx-2=0hoacx+2=0\)
<=>x=0 hoặc x=2 hoặc x=-2
Vậy...
\(x^3-4x=0\)
\(x\left(x^2-4\right)=0\)
\(TH1:x=0\)
\(TH2:x^2-4=0\Rightarrow x^2=4\Rightarrow x=2,x=-2\)
\(x^3-4x=0\)
\(x\left(x-2\right)\left(x+2\right)=0\)
\(\Rightarrow\hept{\begin{cases}x=0\\x=2\\x=-2\end{cases}}\)
vậy...
\(x^3-4x=0\)
\(\Leftrightarrow x\left(x^2-4\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x^2-4=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=\pm2\end{cases}}\)
\(x^3-4x=0\)
\(\Leftrightarrow x\left(x^2-4\right)=0\)
\(\Leftrightarrow x\left(x+2\right)\left(x-2\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=\pm2\end{cases}}\)
Mình làm theo 2 cách nhé, xin lỗi bạn nhiều
Thanks các bạn nha
x3- 4x = 0
\(\Leftrightarrow x\times\left(x^2-4\right)=0\)
\(\orbr{\begin{cases}x=0\\x^2-4=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=2\end{cases}}\)
-HỌC TỐT-
Trả lời:
\(x^3-4x=0\)
\(\Leftrightarrow x\left(x^2-4\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x^2-4=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x^2=4\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=\pm2\end{cases}}\)
Vậy \(x\in\left\{-2;0;2\right\}\)
Hok tốt!
Vuong Dong Yet