\frac{dx_{1}}{dt} = \left(-1 \cdot k_{1} \cdot k_{3} \cdot x_{1} / \left(k_{2} + x_{1}\right) + 1 \cdot k_{1} \cdot k_{11} \cdot x_{5} \cdot k_{19} / \left(\left(x_{5} + k_{12}\right) \cdot \left(k_{19} + k_{13}\right)\right)\right) / k_{1}\\
\frac{dx_{2}}{dt} = \left(2 \cdot k_{1} \cdot k_{3} \cdot x_{1} / \left(k_{2} + x_{1}\right) + -1 \cdot k_{1} \cdot k_{4} \cdot x_{2} \cdot k_{19} / \left(\left(x_{2} + k_{5}\right) \cdot \left(k_{19} + k_{6}\right)\right) + -1 \cdot k_{1} \cdot k_{15} \cdot x_{2} / \left(k_{14} + x_{2}\right)\right) / k_{1}\\
\frac{dx_{3}}{dt} = \left(1 \cdot k_{1} \cdot k_{4} \cdot x_{2} \cdot k_{19} / \left(\left(x_{2} + k_{5}\right) \cdot \left(k_{19} + k_{6}\right)\right) + -1 \cdot k_{1} \cdot k_{8} \cdot x_{3} / \left(k_{7} + x_{3}\right)\right) / k_{1}\\
\frac{dx_{4}}{dt} = \left(1 \cdot k_{1} \cdot k_{8} \cdot x_{3} / \left(k_{7} + x_{3}\right) + -1 \cdot k_{1} \cdot k_{10} \cdot x_{4} / \left(k_{9} + x_{4}\right) + -1 \cdot k_{1} \cdot k_{17} \cdot x_{4} / \left(k_{16} + x_{4}\right)\right) / k_{1}\\
\frac{dx_{5}}{dt} = \left(\frac{3}{5} \cdot k_{1} \cdot k_{10} \cdot x_{4} / \left(k_{9} + x_{4}\right) + -1 \cdot k_{1} \cdot k_{11} \cdot x_{5} \cdot k_{19} / \left(\left(x_{5} + k_{12}\right) \cdot \left(k_{19} + k_{13}\right)\right)\right) / k_{1}\\
\frac{dx_{6}}{dt} = 0\\
\frac{dx_{7}}{dt} = 0