Profit = selling price-cost price (purchase price); Profit rate = (profit/cost price) x100%; Discount rate = discount price/original price; Selling price = cost price+profit = cost price X( 1+ profit rate) = list price x discount rate.

Purchase price: the price (sometimes called cost price) at which the goods are purchased. Selling price: the selling price (sometimes also called transaction price and selling price) when selling goods. List price: the price indicated at the time of sale (sometimes called original price, fixed price). Profit: net income in the process of selling goods, profit = selling price-buying price; Purchase price+price increase = price list.

The concept of sales: profit rate: the percentage of profit in the purchase price, that is, profit rate = profit purchase price x 100%.

The discount sales formula of linear equation of one yuan is: original sales price = purchase price ×( 1+ original profit rate), actual sales price = purchase price ×( 1+ actual profit rate), and discount sales are commercial discounts limited to commodity prices.

The essence of discount sales is the price concessions that sellers give to buyers when selling goods or taxable services. Discount sales is a kind of commercial discount, which refers to the price concessions given to buyers to promote sales because of the large number of buyers when sellers sell goods or provide taxable services.

This method is often short-term, with special conditions and temporary. Such as bulk discount, one-time clearance discount, etc. Because the discount sales are deducted before the transaction is established and the actual payment is made, it has no impact on accounts receivable and operating income, and the accounting records are only treated as the net amount after deducting the commercial discount from the commercial pricing.

Discount sales should pay attention to two points:

1. The discount sales here are limited to the discount of commodity prices. If the seller of goods takes the goods produced, processed or purchased by the seller as a physical discount, the physical price cannot be deducted from the sales of goods, but the VAT output tax should be calculated and paid separately according to the eighth item of "free gift" in the goods sold.

2. According to the Provisions of State Taxation Administration of The People's Republic of China, People's Republic of China (PRC) on Some Specific Issues of Value-added Tax (Guo Shui Fa 1993 document 154), taxpayers sell goods at a discount. If the sales amount and discount amount are indicated on the same invoice, value-added tax can be levied according to the discounted sales amount; If the discount amount is invoiced separately, it shall not be deducted from the sales amount regardless of the financial treatment.