Love My Pet Foods produces dog food, made from beef products and grain. Each pound of beef costs $1.35, and each pound of grain costs $0.82. A pound of the dog food must contain at least 10 units of Vitamin 1 and 9 units of Vitamin 2. A pound of beef contains 8 units of Vitamin 1 and 11 units of Vitamin 2. A pound of grain contains 12 units of Vitamin 1 and 7 units of Vitamin 2. How many pounds of beef and grain should be included in each pound of dog food to minimize total cost? Formulate a linear programming model for the above situation by determining (a) The decision variables (b) Determine the objective function. What does it represent? (c) Determine all the constraints. Briefly describe what each constraint represents.