C.16 Solve linear equations with variables on both sides: word problemsH9GDeb is ordering two pizzas, and she is trying to figure out which of her coupons will give her the best deal. One coupon allows her to buy a pizza at full price and get a second pizza for half off. Another coupon gives her $12 off the total if she buys two pizzas at full price. After considering her options, Deb realizes that the total cost would be the same with either coupon.Which equation can you use to find p, the full price of one pizza?What is the full price of one pizza?$

1 answer

To solve this problem, we need to set up an equation based on the information given about the two coupons.

  1. First coupon: Buy one pizza at full price and get a second pizza at half off.

    • The cost for the first pizza: \( p \) (where \( p \) is the full price of one pizza).
    • The cost for the second pizza at half off: \( \frac{p}{2} \).
    • Total cost with the first coupon: \[ p + \frac{p}{2} = \frac{2p}{2} + \frac{p}{2} = \frac{3p}{2} \]
  2. Second coupon: Get $12 off the total if she buys two pizzas at full price.

    • The cost for two pizzas at full price: \( 2p \).
    • Total cost with the second coupon: \[ 2p - 12 \]

Now, since Deb realized that the total cost would be the same with either coupon, we can set up the following equation: \[ \frac{3p}{2} = 2p - 12 \]

To solve for \( p \), we'll first eliminate the fraction by multiplying the entire equation by 2: \[ 3p = 4p - 24 \]

Next, we will isolate \( p \) by rearranging the equation: \[ 3p - 4p = -24 \ -p = -24 \]

Multiplying both sides by -1 gives: \[ p = 24 \]

Thus, the full price of one pizza is $24.