Need help setting up system of equations!

A pizza shop delivered 18 pepperoni pizzas to a college in the first right of final exams. The total cost of the pizza was$129. A small pizza costs $4 and contains 3 ounces of pepperoni. A medium pizza costs $7 and contains 8 ounces of pepperoni. A large pizza cost $ 12 and contains 11 ounces of pepperoni.

The owner of the pizza shop used 117 ounces of pepperoni in making the 18 pizzas. How many pizzas of each size were delivered to the college?

Question

Need help setting up system of equations!

A pizza shop delivered 18 pepperoni pizzas to a college in the first right of final exams. The total cost of the pizza was$129. A small pizza costs $4 and contains 3 ounces of pepperoni. A medium pizza costs $7 and contains 8 ounces of pepperoni. A large pizza cost $ 12 and contains 11 ounces of pepperoni.

The owner of the pizza shop used 117 ounces of pepperoni in making the 18 pizzas. How many pizzas of each size were delivered to the college?

stefrheart · Answer

You should start with finding what your x and y are going to be

stefrheart · Answer

@Helper321

anonymous · Answer

i believe there are going to be 3 variables and im unsure how to set them up into 3 equations

stefrheart · Answer

Oh yes im sorry there is an x,y, and z

stefrheart · Answer

Let x represent the number of small pizzas
y represent the number of medium pizzas 
and let z represent the number of large pizzas

stefrheart · Answer

What equations do you think we can make? Or is that the part you are having a hard time on, setting up the equations?