a: =>x-5=3 hoặc x-5=-3
=>x=8 hoặc x=2
b: =>|x-1|=7
\(\Leftrightarrow\left[{}\begin{matrix}x-1=7\\x-1=-7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=8\\x=-6\end{matrix}\right.\)
c: \(\Leftrightarrow\left[{}\begin{matrix}2x+5=1\\2x+5=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=-3\end{matrix}\right.\)