a) Use the direct substitution method to find the limit of stability for the system whose characteristic equation is: s3+3s2+3s+(1+k)=0withrespecttok. b) Use Routh criterion to determine the stability of the system whose characteristic equation is: s4+6s3+11s2+6s+5=0 QUESTION 5 a) Consider the Project shown in the Table below: (i) Construct the Network for the Project. (ii) Determine the Critical Path and Project completion time: b) In the solution of the LPP below; Maximize P=7x1+10x2 Subject to: 2x1+x2150 4x1+3x2180x1+x2100 (i) Use Simplex Method show the artificial variable. (ii) Explain why it should be added