The equivalence relation in this problem: it is still profitable to sell at a 20% discount on the list price, that is, 20% discount on the list price-cost price =20 yuan. Solution: Solution: The list price of this sportswear is X yuan.
According to the meaning of the question: 0.8x- 100=20, the solution: x = 150.
A: The price of this sportswear is 150 yuan. Comments: The key to solving the problem is to understand the meaning of the topic, find out the appropriate equivalence relationship, list the equations according to the conditions given by the topic, and then solve it.
2. the road from a to b has a flat road and an uphill road. If you ride a bike on a level road 15km/h, uphill 10km/h, downhill 18km/h, it takes 29 minutes from a to b and 25 minutes from b to a, what is the distance from a to b? Test center: the application of one-dimensional linear equation. Special topic: Travel problem. Analysis: This question first draws the equivalence relation according to the meaning of the question, that is, the distance from A to B is constant, and then lists the equation as10 (2960-x) =18 (2560-x), so as to solve the equation and answer it. Answer: Solution: Ping.
29 minutes = 2960 hours, 25 minutes = 2560,
According to the meaning of the question:10 (2960-x) =18 (2560-x),
Solution: x= 13,
Then the distance from A to B is15×13+10× (2960-13) = 6.5km,
Answer: The distance from A to B is 6.5 kilometers ... Comments: This question mainly investigates the application of linear equation of one variable. The key to solving problems is to master the general steps of solving problems through column equations, that is, ① to find the equivalent relationship according to the meaning of the questions; ② List the equations; ③ Solve equations.
In 2009, the total water consumption for production and operation in Beijing was 580 million cubic meters, of which domestic water consumption was 60 million cubic meters more than that for production and operation. How many cubic meters are used for production, operation and life respectively? Test center: the application of one-dimensional linear equation. Special topic: application problem. Analysis: The equivalent relationship is: household water consumption = 3 times of production and operation water consumption +0.6. Solution: Solution: If the production and operation water consumption is X billion cubic meters, the household water consumption is (5.8-x-X) billion cubic meters.
According to the question, it means 5.8-x=3x+0.6.
Solution: x= 1.3,
∴5.8-x=5.8- 1.3=4.5.
A: The production and operation water consumption is 65.438+0.3 billion cubic meters, and the domestic water consumption is 450 million cubic meters. Comments: The key to solving the problem is to find out the meaning of the problem and find the appropriate equivalent relationship. This problem can also be listed according to "the total production, operation and domestic water consumption is 580 million cubic meters".