\(|x_1-x_2|=x_1+x_2\)
Với \(x_1-x_2\ge0\Leftrightarrow x_1\ge x_2\) thì: \(x_1-x_2=x_1+x_2\)
\(\Leftrightarrow-2x_2=0\Leftrightarrow x_2=0\Leftrightarrow x_1\ge0\)
Với \(x_1-x_2< 0\Leftrightarrow x_1< x_2\) thì: \(x_2-x_1=x_1+x_2\Leftrightarrow-2x_1=0\Leftrightarrow x_1=0\Leftrightarrow x_2>0\)
Phương trình có 2 cặp nghiệm: \(\left[{}\begin{matrix}\left\{{}\begin{matrix}x_2=0\\x_1\ge0\end{matrix}\right.\\\left\{{}\begin{matrix}x_1=0\\x_2>0\end{matrix}\right.\end{matrix}\right.\)
|x1-x2|=x1+x2
x1+x2≥0
x1^2+x2^2-2x1.x2=x1^2+x2^2+2x1x2
<=>x1.x2=0
(x1,x2)=(0,x2€R+); (x1€R+; 0)
