The document provides instructions to write a MATLAB code to simulate a system of ordinary differential equations modeling a chemical reaction. The code should use the Runge-Kutta-Fehlberg and a lower order Runge-Kutta method to integrate the equations forward in time until the concentrations reach equilibrium (x=0). It asks to study the accuracy of the methods by checking how close the final concentrations are to zero, and to plot the time history of the concentrations.