The senior class purchased pizza to sell after school for $320. If they sell pizza by the slice they make $2 per slice. If they
sell a whole pizza it's $10. Each pizza has 8 slices. Let u represent the number of slices sold and let y represent the number of whole
pizzas sold. If the class has 40 pizzas to sell, what is the greatest number of pizzas they can sell if they want to make a profit of
at least $140.
