A bakery makes $4 profit on its wedding cakes x1 and $3 on its birthday cakes x2. Wedding cakes take 4 minutes for mixing, 90 minutes for baking, and 8 minutes for icing. Birthday cakes take 6 minutes for mixing, 15 minutes for baking, and 4 minutes for icing. The bakery has 120 minutes of mixing time, 900 minutes of baking time, and 96 minutes of icing time. Express the data in terms of equations and inequalities necessary to determine the combination of wedding cakes and birthday cakes that will maximize profit subject to the constraints.