Question

How do you solve #18?

Answer 1

Pizzas are circles. Area of circles is (pi)r^2.

Then find the cost per in.^2

Smallest cost per in.^2 is better buy.

Answer 2

The formula for area is A = pi × radius^2. In this case, you are given diameter. Cut the diameter in half yo find the radius and plug the radius into the equation (Ex: for the first pizza the setup would be A = pi × 4^2.)