$***$ Given the following daily nutritional requirements and the nutritional content per unit of

three different foods, we want to minimize the total cost of the diet while satisfying these

nutritional needs: $($i$)$ Protein: at least $50$ grams $($ii$)$ Carbohydrates: at least $300$ grams $($iii$)$

Fat: at least $70$ grams.

Provide a linear programming formulation.