I'm doing an analysis of a paper, and I want to reproduce a plot in the paper where they have the nullclines of two functions, namely: $$ \begin{align}\frac{dW}{dt}&=\ \beta(1-\rho)W+\delta A - \mu N W - \frac{\mu\gamma AW}{1+\rho\theta W}-\alpha N W = 0\\ \frac{dA}{dt}&=\ \alpha N W - \mu N A - \frac{\mu\gamma A^2}{1+\rho\theta W}=0 \end{align}$$
These functions are proving quite difficult to plot the nullclines for, or maybe there's something simple that I can't see. I tried to isolate either $W$ or $A$ on either side but that didn't seem to do much. It's worth noting that $W$ and $A$ are the variables I am interested in (population sizes) and $N=A+W$ (total population, all other variables are just parameters of the system.
My goal is to plot these functions equal to zero in Python, and usually isolating one variable or another works, but I can't seem to make it work.
Any help is appreciated, and thanks in advance.