Evaluate the numerical expression and match to its value

On a piece of paper graph f(x)=5•(0.4)^x

Arestaurant offers delivery for their pizzas. the total cost the customer pays is the price of the pizzas, plus a delivery fee. one customer pays $23 to have 2 pizzas delivered. another customer pays $59 for 6 pizzas. how many pizzas are delivered to a customer who pays $86?

The bottom of a vase is a square.each side measury y+11 units.the square has a perimeter of 55 units what is the value of y?