Question

Three pizzas and four sandwiches cost $34. Three pizzas and seven sandwiches cost $41.50. How much does a pizza,
p, and a sandwich, s, cost?

Answer 1

Answer: p= $8   s= $2.50

Step-by-step explanation:

3p + 4s = 34       and       3p + 7s= 41.50

Since the number of pizzas DIDNT change between these two equations, we can use the total of the second equation to help us find the price of one sandwich.

41.50 - 34 = $7.5 for 3 sandwiches  (7s-4s)

So how much is one sandwich?  7.50/3 = $2.50 for each sandwich

now that we know  s, it’ll be much easier finding p. We can use one equation to find p.

3p + 4(2.5) = 34    (Solve algebraically)

3p + 10 = 34

    - 10  |  -10

3p = 24

3p/3 = 24/3

p = $8.        Now you can check by substituting the variables!