a ) \(\left|2x-3\right|=\left|x+5\right|\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}2x-3=x+5\\2x-3=-x+5\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}2x-x=5+3\\2x+x=5+3\end{array}\right.\Leftrightarrow\left[\begin{array}{nghiempt}x=8\\3x=8\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x=8\\x=\frac{8}{3}\left(loại\right)\end{array}\right.\)
Vậy ...........
b ) \(\left|x\right|+2x=7\)
\(\Rightarrow\left[\begin{array}{nghiempt}-x+2x=7\\x+2x=7\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=7\\3x=7\end{array}\right.\Rightarrow\left[\begin{array}{nghiempt}x=7\left(loại\right)\\x=\frac{7}{3}\end{array}\right.\)
Vậy .........................
c ) \(\left|x\right|+2x=7\) ( giống câu b )
