Nhầm Sửa lại :
\(\left|5x-3\right|-x=7\)
\(\Leftrightarrow\left|5x-3\right|=7+x\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}5x-3=7+x\\3-5x=7+x\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x=\frac{5}{2}\\x=-\frac{2}{3}\end{array}\right.\)
Vậy \(x\in\left\{\frac{5}{2};-\frac{2}{3}\right\}\)
|5x-3|-x=7
=>|5x-3|=7+x
=>5x-3=-(7+x) hoặc 7+x
Xét 5x-3=-(7+x)
=>5x-3=-7-x
=>6x=-4
=>\(x=-\frac{2}{3}\)
Xét 5x-3=7+x
=>2x=5
=>\(x=\frac{5}{2}\)
\(\left|5x-3\right|-x=7\)
\(\Leftrightarrow\left|5x-3\right|=7+x\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}5x-3=7+x\\3-5x=7+x\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}5x-x=7+3\\-5x-x=7-3\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}4x=10\\-6x=4\end{array}\right.\Leftrightarrow\left[\begin{array}{nghiempt}x=\frac{5}{2}\\x=-\frac{2}{3}\left(KTMĐK\right)\end{array}\right.\)
Vậy \(x=\frac{5}{2}\)
