Cho số phức $z$ thỏa mãn $\left( 2+3i \right)z=z-1$. Môđun của...

Ta có \)">\left( 2+3i \right)z=z-1\Leftrightarrow \left( 1+3i \right)z=-1\Leftrightarrow z=\dfrac{-1}{1+3i}=\dfrac{-1.\left( 1-3i \right)}{10}\Leftrightarrow z=\dfrac{-1}{10}+\dfrac{3i}{10}\Leftrightarrow \overline{z}=\dfrac{-1}{10}-\dfrac{3i}{10}\left| \overline{z} \right|=\sqrt{{{\left( \dfrac{-1}{10} \right)}^{2}}+{{\left( \dfrac{-3}{10} \right)}^{2}}}=\dfrac{1}{\sqrt{10}}$.