Answer:
To compare the two pizzas, we need to calculate their prices per unit area.
Area of a 10-inch pizza = pi x (5)^2 = 78.5 square inches
Price per square inch = $8.99 / 78.5 = $0.1144 per square inch
Area of a 6-inch pizza = pi x (3)^2 = 28.3 square inches
Price per square inch = $5 / 28.3 = $0.1767 per square inch
So the 10-inch pizza is a better buy, as it has a lower price per square inch compared to the 6-inch pizza.