\frac{dx_{1}}{dt} = \left(-1 \cdot k_{15} \cdot x_{1} \cdot \left(1 - k_{6} \cdot \left(k_{14} \cdot k_{9} + k_{14} \cdot \left(1 - \left(k_{9} + k_{10}\right)\right) + k_{14} \cdot k_{10}\right) / k_{5}\right) \cdot k_{3} + -1 \cdot k_{15} \cdot x_{1} \cdot \left(1 - \left(1 - k_{6} \cdot \left(k_{14} \cdot k_{9} + k_{14} \cdot \left(1 - \left(k_{9} + k_{10}\right)\right) + k_{14} \cdot k_{10}\right) / k_{5}\right) \cdot k_{3}\right)\right) / k_{19}\\ \frac{dx_{2}}{dt} = \left(1 \cdot k_{15} \cdot x_{1} \cdot \left(1 - k_{6} \cdot \left(k_{14} \cdot k_{9} + k_{14} \cdot \left(1 - \left(k_{9} + k_{10}\right)\right) + k_{14} \cdot k_{10}\right) / k_{5}\right) \cdot k_{3} + -1 \cdot k_{14} \cdot k_{9} \cdot x_{2} + -1 \cdot k_{14} \cdot k_{10} \cdot x_{2} + -1 \cdot k_{14} \cdot \left(1 - \left(k_{9} + k_{10}\right)\right) \cdot x_{2}\right) / k_{20}\\ \frac{dx_{3}}{dt} = \left(1 \cdot k_{14} \cdot k_{10} \cdot x_{2} + -1 \cdot k_{16} \cdot x_{3}\right) / k_{21}