minimization problem (linear programming)

a veterenarian mixes two types of animal food: Food 1 and Food 2. Each unit of Food 1 costs 200 and contains 40 grams of fat, 30 grams of protein and 1200 calories. Each unit of Food 2 costs 250 and contains 80 grams of fat, 60 grams of protein, and 1600 calories. Suppose the vet wants each unit of the final product to yield not more than 360 grams of fat, at least 240 grams of protein and at least 9600 calories, how many grams of each type of ingredient should the vet use to minimize his cost?

*ive defined the variables and constraints. but not so sure about it. the problem is i cant find the feasible region and the optimal mix when the lines are put in a graph.

thanx ahead! :)

** Let X1= Food 1; x2= Food 2

objective function= minimize Z= 200x1+250X2

constraints:

1. 40x1 + 80x2 less than or equal to 360

2. 30x1 + 60x2 greater than or equal to 240

3. 1200x1 + 1600x2 greater than or equal to 9600

4. non negativity constraints