Please show ALL Matlab steps. Thank you!

3. A flow of water at 2000kPa,20AEAC is mixed with a flow of 12kg/s water at 2000 kPa,180AEAC. What should the flowrate of the first flow be to produce an exit state of 200kPa and 100AEAC ? It is known that at enthalpy, h1(2000kPa,20EAC)EA= 85.8kJ/kg;h2(2000kPa,180EAC)EA=763.7kJ/kg;hA3(200kPa,100EAC)EA= 419.0kJ/kg. Requirement: Use Matlab to solve the linear equations about mass and energy balance