What is the price per square inch of the better buy: A large pizza with an 18 inch diameter for $20, or a medium pizza with a 14 inch diameter for $14?

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:

A large pizza with an 18 inch diameter for $20

The radius is half the diameter, so .

In square inches, the area is:

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

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.

the volume is the product of the area of the base, 3x(3x+4), and the height, 3x-1

step-by-step explanation:

take the logarithm of both sides (the base of the log doesn't matter):

apply the exponent property - this says that :

distribute the log terms on both sides:

group like terms together:

divide through both sides by the coefficient on :

you can do some additional rewriting here using the properties of the logarithm to simplify things if you like: