e) \(x\left(x-2\right)+\left(2-x\right)=0\)
\(\Leftrightarrow x\left(x-2\right)-\left(x-2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x-2=0\\x-1=0\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=2\\x=1\end{array}\right.\)
\(x\left(x-2\right)+\left(2-x\right)=0\)
\(x\left(x-2\right)+.-\left(x-2\right)=0\)
\(x\left(x-2\right)-\left(x-2\right)=0\)
\(\left(x-1\right)\left(x-2\right)=0\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x-1=0\\x-2=0\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x=1\\x=2\end{array}\right.\)
Vậy \(x\in\left\{1;2\right\}\)
