There are two factors that limit how much he can bake in a week: He only wants to work for 40 a week and he only has one oven. Suppose that it takes the baker 1 to prepare a pair of cakes or a gross of cookies (before they are placed in the oven). Since he only wants to work 40 a week, his output of pairs of cakes and his output of grosses of cookies are constrained by the equation .
To maximize the profit of the bakery, the first step is to find where the equations for all of the constraints intersect. For the following part, you will look at and , which is also a constraint (specifically a minimum) since the baker cannot make a negative number of cookies.
What should you multiply the equation by so that when added to the variable will cancel out?