Final answer:
The cost of a purchase with 20% off the original price p and taxed at 8.5% is represented by the expression (p - (0.20 × p)) + (0.085 × (p - (0.20 × p))). This calculates the discounted price and then adds the tax on the discounted amount.
Step-by-step explanation:
To write an expression that models the cost of a purchase that is 20% off the original price p, and is then taxed at 8.5%, we follow these steps:
- Determine the discount amount by multiplying the original price by 20%. This can be represented as 0.20 × p.
- Subtract the discount from the original price to get the discounted price: p - (0.20 × p).
- Calculate the tax by multiplying the discounted price by 8.5%. The expression for this is 0.085 × (p - (0.20 × p)).
- Add the tax to the discounted price to obtain the final cost of the purchase. The complete expression would be (p - (0.20 × p)) + (0.085 × (p - (0.20 × p))).
This expression simplifies the process of calculating the final price after the given discounts and tax have been applied.