Sum of solutions of the equation $|\mathrm{x}{|}^3-4|\mathrm{x}{|}^2+3\left|\mathrm{x}\right|=0$ is

We have $|\mathrm{x}{|}^3-4|\mathrm{x}{|}^2+3\left|\mathrm{x}\right|=0$

$\begin{array}{l}\Rightarrow \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\left|\mathrm{x}\right|\left(|\mathrm{x}{|}^2-4|\mathrm{x}|+3\right)=0\\ \Rightarrow \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\left|\mathrm{x}\right|\left(\right|\mathrm{x}|-1)\left(\right|\mathrm{x}|-3)=0\\ \Rightarrow \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\left|\mathrm{x}\right|=0,1,3\\ \Rightarrow \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\mathrm{x}=0,1,3,-1,-3\end{array}$