4. (total 25 points) Consider the following linear program P: Maximize Subject to Z=4x + 3x2 + 6x3 3x1 + x2 + 3x3 30 2x+2x2 + 3x3 40 and X1, X2, X3 20 (1) (5 points) Provide an initial basic feasible solution in solving problem P. Hint: Use x4, X5, in sequence to denote slack, surplus variables. (2) (5 points) In a Simplex iteration, the current basis is 30 B = 3 1 " which corresponds to basic variables x3 and x5. Please compute the current basic feasible solution.