Exhibit a linear programming problem with two variables for which both the primal and the dual are infeasible. Show that the classical dual of min{cx | Ax = b, x ≥ 0} is the problem max{ub | uA ≤ c},...

Exhibit a linear programming problem with two variables for which both

the primal and the dual are infeasible.

Show that the classical dual of min{cx | Ax = b, x ≥ 0} is the problem

max{ub | uA ≤ c}, where u is not restricted to be nonnegative.