Question

Lesson 5 Practice Problems

1. A restaurant offers delivery for their pizzas. The total cost is a delivery fee added to
the price of the pizzas. One customer pays $25 to have 2 pizzas delivered. Another
customer pays $58 for 5 pizzas. How many pizzas are delivered to a customer who
pays $80?
Be sure to completely explain your answer.
When explaining, make it sound like you are talking to a grandma.

Answer 1

Let the price of a pizza be x
Delivery charge be y
Cost of two pizzas = 2*x
2x+y=25. ————-(1)
Y=25-2x
Cost of 5 pizza = 5*x
5x+y=58. —————-(2)
Substitute y=25-2x in equation 2
5x +25-2x=58
3x+25=58
Subtract 25 from both sides
3x =58-25
3x=33
Divide both sides by 3
X=33/3
X=11
Plug-in x= 11 in equation 1
2*11+y=25
22+y=25
Y=25-22
Y=3
Cost of a pizza =$11
Delivery charge=$3

80-3=77
Number of pizzas delivered=77/11=7


7 pizzas are delivered