I can't figure this out.

An objective function and a system of linear inequalities representing constraints are given. Complete parts a. 45- through c. Objective Function z = 3x + 5y Constraints x 20, y 20 2x + y s 14 x+y27 a. Graph the system of inequalities representing the - 15 12 - 12 15 constraints. Use the graphing tool to graph the system. b. Find the value of the objective function at each corner of the graphed region. (Use a comma to separate answers as needed.) c. Use the values in part (b) to determine the maximum value of the objective function and the values of x and y at which the maximum occurs. The maximum value of the objective function is Find the values of x and y at which the maximum occurs. X