\frac{dx_{1}}{dt} = \left(-1 \cdot k_{13} \cdot \left(k_{1} \cdot x_{1} \cdot x_{3} - k_{9} \cdot x_{2}\right) + 1 \cdot k_{13} \cdot k_{2} \cdot x_{2} + -1 \cdot k_{13} \cdot \left(k_{3} \cdot x_{1} \cdot x_{4} - k_{10} \cdot x_{5}\right) + 1 \cdot k_{13} \cdot k_{4} \cdot x_{5} + -1 \cdot k_{13} \cdot \left(k_{5} \cdot x_{1} \cdot x_{3} - k_{11} \cdot x_{7}\right) + 1 \cdot k_{13} \cdot k_{6} \cdot x_{7} + -1 \cdot k_{13} \cdot \left(k_{7} \cdot x_{1} \cdot x_{8} - k_{12} \cdot x_{9}\right) + 1 \cdot k_{13} \cdot k_{8} \cdot x_{9}\right) / k_{13}\\
\frac{dx_{2}}{dt} = \left(1 \cdot k_{13} \cdot \left(k_{1} \cdot x_{1} \cdot x_{3} - k_{9} \cdot x_{2}\right) + -1 \cdot k_{13} \cdot k_{2} \cdot x_{2}\right) / k_{13}\\
\frac{dx_{3}}{dt} = \left(-1 \cdot k_{13} \cdot \left(k_{1} \cdot x_{1} \cdot x_{3} - k_{9} \cdot x_{2}\right) + -1 \cdot k_{13} \cdot \left(k_{5} \cdot x_{1} \cdot x_{3} - k_{11} \cdot x_{7}\right)\right) / k_{13}\\
\frac{dx_{4}}{dt} = \left(1 \cdot k_{13} \cdot k_{2} \cdot x_{2} + -1 \cdot k_{13} \cdot \left(k_{3} \cdot x_{1} \cdot x_{4} - k_{10} \cdot x_{5}\right)\right) / k_{13}\\
\frac{dx_{5}}{dt} = \left(1 \cdot k_{13} \cdot \left(k_{3} \cdot x_{1} \cdot x_{4} - k_{10} \cdot x_{5}\right) + -1 \cdot k_{13} \cdot k_{4} \cdot x_{5}\right) / k_{13}\\
\frac{dx_{6}}{dt} = \left(1 \cdot k_{13} \cdot k_{4} \cdot x_{5} + 1 \cdot k_{13} \cdot k_{8} \cdot x_{9}\right) / k_{13}\\
\frac{dx_{7}}{dt} = \left(1 \cdot k_{13} \cdot \left(k_{5} \cdot x_{1} \cdot x_{3} - k_{11} \cdot x_{7}\right) + -1 \cdot k_{13} \cdot k_{6} \cdot x_{7}\right) / k_{13}\\
\frac{dx_{8}}{dt} = \left(1 \cdot k_{13} \cdot k_{6} \cdot x_{7} + -1 \cdot k_{13} \cdot \left(k_{7} \cdot x_{1} \cdot x_{8} - k_{12} \cdot x_{9}\right)\right) / k_{13}\\
\frac{dx_{9}}{dt} = \left(1 \cdot k_{13} \cdot \left(k_{7} \cdot x_{1} \cdot x_{8} - k_{12} \cdot x_{9}\right) + -1 \cdot k_{13} \cdot k_{8} \cdot x_{9}\right) / k_{13}