Referring to a system of equation from aligned environment

Question

I have a system of equations and I used aligned environment to get a one number as label se here but I am not able to refer to it. I searched here and other places but all shows how to refer to equation when it is labeled using \label. However using label in aligned environment with \begin equation doesn't work.

\documentclass[14pt, a4paper, twoside]{report} 
\usepackage{amsmath}
\begin{document}
\begin{equation} 
\begin{aligned}
\frac{d\bar{x}(\tau)}{d\tau}=\quad&\bar{x}\left[1-\bar{x}-\bar {y}_{1}-\bar{y} _{2} \right] +\bar{s}(\tau),\quad \bar{x}(0)>0\\
\frac{d\bar{y}_{1}(\tau)}{d\tau}=\quad& \bar{y}_{1} \left[-\bar{\epsilon}_{1}-\bar{\omega}_{11}\bar {y}_{1}-\bar{g}_{12}\bar{y}_{2}+\bar{\beta}_{1}\bar{x}\right],\quad \bar{y}_{1}(0)>0 \\
\frac{d\bar{y}_{2}(\tau)}{d\tau}=\quad& \bar{y}_{2} \left[-\bar{\epsilon}_{2}+\bar{\gamma_{12}}\bar{y}_{1}-\bar{\omega}_{22}\bar {y}_{2}+\bar{\beta}_{2}\bar{x}\right],\quad \bar{y}_{2}(0)>0 \\
\end{aligned}
\end{equation}
\end{document}

In my document the system get the label (5.1) because it is inside chapter 5 but I want to refer to this other places. I can of course just write (5.1) but want more systematic way.

Answer 1

You can reference the equation number using \label and \ref (or \eqref which adds parenthesis) the fact that the equation contains an aligned does not affect things at all.

\documentclass[14pt, a4paper, twoside]{report} 
\usepackage{amsmath}
\begin{document}
\begin{equation}\label{foo}
\begin{aligned}
\frac{d\bar{x}(\tau)}{d\tau}=\quad&\bar{x}\left[1-\bar{x}-\bar {y}_{1}-\bar{y} _{2} \right] +\bar{s}(\tau),\quad \bar{x}(0)>0\\
\frac{d\bar{y}_{1}(\tau)}{d\tau}=\quad& \bar{y}_{1} \left[-\bar{\epsilon}_{1}-\bar{\omega}_{11}\bar {y}_{1}-\bar{g}_{12}\bar{y}_{2}+\bar{\beta}_{1}\bar{x}\right],\quad \bar{y}_{1}(0)>0 \\
\frac{d\bar{y}_{2}(\tau)}{d\tau}=\quad& \bar{y}_{2} \left[-\bar{\epsilon}_{2}+\bar{\gamma_{12}}\bar{y}_{1}-\bar{\omega}_{22}\bar {y}_{2}+\bar{\beta}_{2}\bar{x}\right],\quad \bar{y}_{2}(0)>0 \\
\end{aligned}
\end{equation}

see \eqref{foo}
\end{document}