Show Both the Network and the Linear Programming Formulation for This

Essay

Show both the network and the linear programming formulation for this assignment problem. $$\begin{array} { c | c c c c } & &{ \text { Task } } \\\text { Person } & \text { A } & \text { B } & \text { C } & \text { D } \\\hline 1 & 9 & 5 & 4 & 2 \\2 & 12 & 6 & 3 & 5 \\3 & 11 & 6 & 5 & 7\end{array}$$