Answer:
The least number of pizza make deal 1 better than deal 2 is 4
The cost of deal 1 is $53.99 and the cost of deal 2 is $60
The cost per pizza of deal 1 is $5.399
The better deal is deal 1
Explanation:
* Deal 1 becomes better if it costs less than deal 2
- Assume that the number of pizza are n
* Deal 1:
∵ The cost of one large pizza = $8.99 for first 1 and = $5 for each
additional one
∵ They ordered n large pizza
∴ The cost = 8.99 + 5(n - 1)
- Multiply the bracket by 5
∴ The cost = 8.99 + 5n - 5
- Add like terms
∴ The cost = 3.99 + 5n
∴ The cost of deal 1 = 3.99 + 5n
* Deal 2:
∵ The cost of any large pizza is $6
∵ They ordered n large pizza
∴ The cost = 6 × n = 6n
∴ The cost of deal 2 = 6n
- We need Deal 1 better than deal 2
- Then, put the cost of deal 1 < the cost of deal 2
∵ 3.99 + 5n < 6n
- Subtract 5n from both sides
∴ 3.99 < n
∴ n > 3.99
∴ n = 4
* The least number of pizza make deal 1 better than deal 2 is 4
∵ n = 10
∴ The cost of deal 1 = 3.99 + 5(10) = 53.99
∴ The cost of deal 2 = 6(10) = 60
* The cost of deal 1 is $53.99 and the cost of deal 2 is $60
∵ The cost per one pizza = total cost ÷ the number of pizza
∴ The cost per pizza of deal 1 = 53.99 ÷ 10 = 5.399
* The cost per pizza of deal 1 is $5.399
∵ The unit price of deal 1 is $5.399
∵ The unit price of deal 2 is $6
∵ $5.399 < $6
∴ The unit rate of deal 1 is less than the unit price of deal 2
* The better deal is deal 1