a. Using the decision variables x4 and s4, write a constraint that limits next week's production of the 4 -cylinder connecting rods to either 0 or 7,100 units. x4 S4 b. Using the decision variables x6 and s6, write a constraint that limits next week's production of the 6 -cylinder connecting rods to either 0 or 5,100 units. x6,s6 c. Write three constraints that, taken together, limit the production of connecting rods for next week. \begin{tabular}{lll} x4 & : & s4 \\ x6. & s6 & s6 \\ s4+ & & \\ \hline \end{tabular} d. Write an objective function for minimizing the cost of production for next week. Minx4+x6+s4+s6