Solve these problems using graphical linear programming and then answer the questions that follow. Use simultaneous equations to determine the optimal values of the decision variables. a$.$ Minimize Z $=1\mathrm{.}80$S $+2\mathrm{.}20$T Subject to: Potassium $5$S $+8$T $>=200$ grams Carbohydrate $15$S $+6$T $>=240$ grams Protein $4$S $+12$T $>=180$ grams T T $>=10$ grams S$,$T $>=0$ Do any constraints have $($nonzero$)$ slack? If yes, which one$($s$)$ and how much slack does each have? multiple choice $1$ None of the constraints have any slack. The first constraint has a slack of $10.$ The second constraint has a slack of $15.$