Simple linear programming (1) solves the maximum problem of linear objective function under constraints: ① drawing-drawing any straight line L and the parallel straight line system represented by the objective function in the plane area determined by constraints (inequality group); (2) Translating-moving L in parallel to determine the position of the corresponding point of the optimal solution; (3) Evaluation-solving related equations to find the optimal coordinates, and then substituting them into the objective function to find the maximum value of the objective function.