How to solve this problem

Question

The pizza shop sells pizzas that are 10 inches (in diameter) or larger. A 10 inch cheese pizza cost $8. Each additional inch costs $1.50 and each additional topping costs $0.75.

write an equation that represents the cost of a pizza. Specify what the variables represent.

Answer 1

This is a function who's value is cost (C) and which has two (instead of the more common one) independent variable. The cost depends on diameter (d) and number of toppings (t).

The nomenclature for a function C that depends on variables d & t is C(d,t).

The terms of the function include a constant (cost of a 10 inch cheese pizza) and two rates. The rates includes $0.75/topping and $1.50/inch over 10.

C(d,t) = 8 + 0.75 t + 1.50 (d-10)