Shelly has a gift card for her favorite restaurant for $15. She wants to treat a group of her friends to sandwiches at the restaurant. Sandwiches cost $4.50 each. Write an equation that models the total money Shelly owes if she buys x sandwiches after using the gift card.

Amount owed = 4.5x - 15

Step-by-step explanation:

x sandwiches will cost:

$4.50x

She has $15

She has to pay:

$ (4.5x - 15) more

Step-by-step explanation:

the money that Shelly will owe after buying x sandwiches and using the card will be:

if x < 4 then 15 - 4.5x < = 15 - 3*4.5 = 1.5 she will not owe anything plus she will receive change of $1.5.

if x=> 4 then 4.5x - 15 = > 18 - 15 = 3 that is Shelly will owe 4.5x - 15 dollars.