The absorption of component A from the gas mixture A+B with the aid of a liquid solvent is considered in a cascade gas absorption column. a) By clearly showing the currents entering and leaving the column i. Extract the model equations for the step. b) Subtract the model equation for the upper stage. c) Subtract the model equation for the lower stage. d) Obtain the space-state model equation of the system by subtracting the component mass balance equations for the 5 stages.