Question

Here is the problem:

Christopher orders a three topping pizza for $15.25, and a 5 topping pizza for $17.75.
Write and solve a system of linear equations to find the price of a plain cheese pizza (no toppings) and the cost of each topping.

I used the method of elimination to get the answer, "Each pizza topping is $1.15.
When I placed 1.15 into each equation ( 3x + y = 15.25 and 5x + y = 17.75) to get the cost a a plain cheese pizza, I got 11.8 for the first equation and 12 for the second. That's confusing.

I concluded that Each pizza topping is $1.15, and each plain pizza is $12. Is this correct?

Answer 1

x = amount per topping
b = base price for cheese

15.25 = b + 3 x
17.75 = b + 5 x
----------------subtract
-2.5 = -2x
x = 1.25 Not 1.15 I think

17.75 = b + 5 (1.25)
b = 11.50

Answer 2

Thank you very much.