Answer:
The large pizza has the lower cost per square inch, so it is the better buy.
Step-by-step explanation:
A pizza has the format of a circle.
The area of a circle with radius r is given by the following equation:
[tex]A = \pi r^{2}[/tex]
A large pizza with an 18 inch diameter for $20
The radius is half the diameter, so [tex]r = 9[/tex].
In square inches, the area is:
[tex]A = \pi*9^{2} = 81\pi = 254.47[/tex]
254.47 square inches cost $20. So the price per square inch is 20/254.47 = 0.0786.
Medium pizza with a 14 inch diameter for $14:
Radius is 7. So
[tex]A = \pi*7^{2} = 49\pi = 153.938[/tex]
153.938 square inches cost $14. So the price per square inch is 14/153.938 = 0.0909.
The large pizza has the lower cost per square inch, so it is the better buy.
