2. Profit rate = (selling price-purchase price) ÷ purchase price;

3. Original Price = List Price;

4. Purchase price = selling price ÷( 1+ profit rate)

5. Profit = selling price-purchase price (cost price);

6. Profit rate = (profit/cost) ×100%;

7. Profit = selling price _ purchase price

The main forms of profit rate are:

1, sales profit rate.

The ratio of total sales profit to total sales revenue in a certain period. It shows the profit obtained by unit sales revenue and reflects the relationship between sales revenue and profit.

2. Cost profit rate.

The ratio of total sales profit to total sales cost in a certain period. It represents the profit obtained by unit sales cost and reflects the relationship between cost and profit.

3. Profit rate of output value.

The ratio of total sales profit to total output value in a certain period indicates the profit obtained by unit output value and reflects the relationship between output value and profit.

4. Profit rate of funds.

The ratio of total sales profit to average capital occupation in a certain period. It represents the sales profit obtained by unit funds and reflects the utilization effect of enterprise funds.

Basic formula: it is the most important formula in mathematics and the most important way to solve problems in mathematics. Invariance means the basic formula. In other words, no matter how to change it, it is all around the basic formula, and the ultimate goal is to apply the basic formula. For example, the area formula of triangle: triangle area = base x height ÷ 2, which is a basic formula. In the process of solving problems, no matter how to find the bottom, no matter what the bottom has to do with it, no matter how to find the height, no matter what the height has to do with it, the ultimate goal is to go for the basic formula of triangle area = bottom x height ÷ 2. Deformation formula: the deformation formula evolved from the basic formula, but all other relations in the basic formula were written in, which is actually a simplified basic formula.

1. Relationship between profit and selling price, cost price (purchase price), marked price (original price) and discount: Basic formula: profit = selling price-cost price. This formula is easy to understand. Profit is money earned, selling price is how much money is sold, and cost price is the purchase price of goods. Therefore, profit is the money sold, MINUS the money bought, and naturally it is the money earned. Deformation formula: profit = list price x discount-cost price: this relationship is also easy to understand and close to life. Now merchants are willing to use discounts to promote sales. So the selling price becomes "list price x discount". As we know, the marked price, also called original price and fixed price, refers to the price that has not been sold in the store, and the actual transaction price is often a discount on this basis. In fact, the formula "profit = list price x discount-cost price" evolved from "profit = selling price-cost price".