\begin{multline} \left\{\begin{matrix}x=\alpha\left(1-\text{βy}\right)\equiv g\left(y\right)\text{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ }\\ x=\frac{\sigma}{\delta+\text{μy}-\text{ρy}/(n+y)}\equiv f\left(y\right)\\ \end{matrix}\right.\ \end{multline} (8) (9)