Nаsh Autо hаs twо plаnts (nоde number 1 and 2), two warehouses (node number 3 and 4), and two customers (node number 5 and 6). Cars are produced at plants, then shipped to plant, warehouses, and customers. Plant 1 produces 300 cars per week, and Plant 2 produces 500 cars per week. Customer 1 (node number 5) requires 450 cars per week, and customer 2 (node number 6) requires 250 cars. The costs of shipping a car between nodes are listed in the Table. To From 1 2 3 4 5 6 1 $ 3 $ 4 $6 2 $ 4 $ 6 $7 $ 20 3 $4 $8 $10 4 $5 $9 $12 1. Define the decision variables (5 points) 2. Define objective function (5 points) 3. Formulate the constraints of following nodes (20 points)