The following simplex tableau shows the optimal solution of a linear programming problem. it is known that x4 and x5 are the slack variables in the first and second constraints of the original problem. the constraints are of the s type x4 x5 rhs 1/41/405 | 011-1/2 0-1/6 1/3 a. write the original problem. b. what is the dual of the original problem? c. obtain the optimal solution of the dual problem from the tableau.