Question

[=.=]

Tìm x :

\(x^3=x\)

giải cho tiết , ko lm thiếu bươc nhé !

Answer 1

[Lightning Farron]

\(x^3=x\Rightarrow x^3-x=0\)

\(\Rightarrow x\left(x^2-1\right)=0\)\(\Rightarrow\left[\begin{matrix}x=0\\x^2-1=0\end{matrix}\right.\)

\(\Rightarrow\left[\begin{matrix}x=0\\x^2=1\end{matrix}\right.\)\(\Rightarrow\left[\begin{matrix}x=0\\x=\pm1\end{matrix}\right.\)

Answer 2

[Kudo Shinichi]

x³ = x

\(\Rightarrow\) x³ - x = 0

\(\Rightarrow\) x . x² - x . 1 = 0

\(\Rightarrow\) x(x² - 1) = 0

\(\Rightarrow\) \(\left[\begin{matrix}x=0\\x^2-1=0\end{matrix}\right.\) \(\Rightarrow\left[\begin{matrix}x=0\\x^2=0+1\end{matrix}\right.\) \(\Rightarrow\left[\begin{matrix}x=0\\x^2=1\end{matrix}\right.\) \(\Rightarrow\left[\begin{matrix}x=0\\x^2=1^2\end{matrix}\right.\) \(\Rightarrow\left[\begin{matrix}x=0\\x=1\end{matrix}\right.\)

Vậy: x \(\in\) {0; 1}