\frac{dx_{1}}{dt} = k_{3} - \left(k_{2} + k_{1} \cdot x_{2}\right) \cdot x_{1}\\
\frac{dx_{2}}{dt} = x_{3} \cdot k_{4} \cdot x_{1}^{2} / \left(k_{5} + x_{1}^{2}\right) - k_{6} \cdot x_{2}\\
\frac{dx_{3}}{dt} = \left(\left(-k_{7}\right) + k_{8} \cdot x_{1} - k_{9} \cdot x_{1}^{2}\right) \cdot x_{3}