Question

giúp mình câu này với ạ 

Answer 1

\(\left|x-1\right|-2x-3=0\)

\(\Leftrightarrow\left|x-1\right|=3+2x\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=3+2x\\x-1=-\left(3+2x\right)\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2x=3+1\\x-1=-3-2x\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}-x=4\\x+2x=-3+1\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\3x=-2\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-\dfrac{2}{3}\end{matrix}\right.\)

Answer 2

|x-1|-2x-3=0

=>|x-1|=2x+3

TH1:x-1=2x+3

        x-2x=1+3

        -x=4

         x=-4

TH2:-x+1=2x+3

         -x-2x=-1+3

          -3x=2

              x=-2/3

Vậy S={-2/3}