Consider a product mix problem, where the decision involves determining the optimal production levels for products X and Y. A unit of X requires 4 hours of labor in department 1 and 6 hours of labor in department 2. A unit of Y requires 3 hours of labor in department 1 and 8 hours of labor in department 2. Currently, 1000 hours of labor time are available in department 1 , and 1200 hours of labor time are available in department 2. Furthermore, 400 additional hours of cross-trained workers are available to assign to either department (or split between both). Each unit of X sold returns a $50 profit, while each unit of Y sold returns a $60 profit. All units produced can be sold. Formulate this problem as a linear program. (Hint: Consider introducing other decision variables in addition to the production amounts for X and Y.) Question: Provide the mathematical expressions of all constraints