Question

John Anderson knows that the pizza pipeline charges its customers a certain amount per one topping pizza, plus a fixed price for delivery. The checks that John wrote for the last two deliveries were $17 for two pizzas and $31 for four pizzas. How much would each pizza cost without delivery, how much is the fixed delivery charge, and how much wood five pizzas cost with delivery

Answer 1

If the fixed cost is f and the per-pizza cost is p, then we know:

c+2p = 17
c+4p = 31
now subtract and you see that
2p = 14

now you can find p, and then c.

The five pizzas cost c+5p