Question

(b) select the stories represented by this equation.
16x + 8 = 72

• elsa ordered pizzas from a restaurant. she had a coupon discount for $8 off her entire purchase. the restaurant charges x dollars for each pizza, and elsa bought 16 pizzas. she spent a total of $72 after the discount.
• elsa ordered pizzas from a restaurant. she had a coupon discount for $8 off her entire purchase. the restaurant charges $16 for each pizza, and elsa bought x pizzas. she spent a total of $72 after the discount.
• elsa ordered pizzas from a restaurant. there was a delivery fee of $8 for the entire purchase. the restaurant charges $16 for each pizza, and elsa bought x pizzas. she spent a total of $72 including the delivery fee.
• elsa ordered pizzas from a restaurant. there was a delivery fee of $8 for the entire purchase. the restaurant charges x dollars for each pizza, and elsa bought 16 pizzas. she spent a total of $72 including the delivery fee.
• none of the above

Explanation:

1. For the first story: The equation would be $16x - 8 = 72$ (discount subtracts 8), which does not match $16x + 8 = 72$.
2. For the second story: The equation would be $16x - 8 = 72$ (discount subtracts 8), which does not match $16x + 8 = 72$.
3. For the third story: Cost of $x$ pizzas is $16x$, plus $8 delivery fee equals total $72$, so equation is $16x + 8 = 72$, which matches.
4. For the fourth story: The equation would be $16x + 8 = 72$? No, here cost per pizza is $x$, 16 pizzas give $16x$, plus $8 fee equals $72$, which is also $16x + 8 = 72$, this also matches.

Wait, correction: Recheck fourth story: "restaurant charges x dollars for each pizza, and Elsa bought 16 pizzas. There was a delivery fee of $8 for the entire purchase. She spent a total of $72 including the delivery fee." So total cost is $16x + 8 = 72$, which matches the given equation. Third story: "restaurant charges $16 for each pizza, and Elsa bought x pizzas. There was a delivery fee of $8 for the entire purchase. She spent a total of $72 including the delivery fee." So total cost is $16x + 8 = 72$, which matches.

First story uses subtraction (discount), so equation is $16x -8=72$, not matching. Second story also uses subtraction, $16x -8=72$, not matching.

Answer:

• Elsa ordered pizzas from a restaurant. There was a delivery fee of $8 for the entire purchase. The restaurant charges $16 for each pizza, and Elsa bought x pizzas. She spent a total of $72 including the delivery fee.
• Elsa ordered pizzas from a restaurant. There was a delivery fee of $8 for the entire purchase. The restaurant charges x dollars for each pizza, and Elsa bought 16 pizzas. She spent a total of $72 including the delivery fee.