Ta có \(\left\{{}\begin{matrix}x-1< 0\\x+1>0\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x< 1\\x>-1\end{matrix}\right.\) \(\Rightarrow-1< x< 1\Rightarrow x=0\)
\(\left\{{}\begin{matrix}x-1< 0\\x+1>0\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}x< 1\\x>-1\end{matrix}\right.\)\(\Rightarrow x=0\)
x-1<0
nên x<1(1)
x+1>0
nên x>-1(2)
Từ (1) và (2) suy ra -1<x<1
hay x=0