[using binary linear equation] 1. When a ship sails downstream, it travels 20km / h; when it sails upstream, it travels 16km / h. The speed of the ship in still water and the velocity of water are calculated 2. Transport 360 tons of chemical fertilizer, carrying 6 train skins and 15 cars; transport 440 tons of chemical fertilizer, carrying 8 train skins and 10 cars, how many tons of chemical fertilizer are loaded in each train skin and car? 3. When the length of a rectangle is reduced by 5cm and the width is increased by 2cm, it becomes a square, and the areas of the two figures are equal. What are the length and width of the rectangle? There are many points

[using binary linear equation] 1. When a ship sails downstream, it travels 20km / h; when it sails upstream, it travels 16km / h. The speed of the ship in still water and the velocity of water are calculated 2. Transport 360 tons of chemical fertilizer, carrying 6 train skins and 15 cars; transport 440 tons of chemical fertilizer, carrying 8 train skins and 10 cars, how many tons of chemical fertilizer are loaded in each train skin and car? 3. When the length of a rectangle is reduced by 5cm and the width is increased by 2cm, it becomes a square, and the areas of the two figures are equal. What are the length and width of the rectangle? There are many points

1.x+y=20 x-y=16 x=18 y=2
2.6x+15y=360 8x+10y=440 x=50 y=14
3.xy=(x-5)(y+2) x-5=y+2 x=25/3 y=4/3

Ask a few junior mathematics problems, smart to help me solve, to use binary linear equation solution
1》 When logging with rope, if the rope is bent three times, the rope will be five feet more; if the rope is bent four times, the rope will be one foot more

Let the rope length be x and the well length be y
x/3 - 5 = y
x/4 - 1 = y
x=48 y=11

Ask a few mathematical problems, binary linear equation problem! To junior one degree or above eugenics
1. Party A and Party B run on the circular road at the same speed. If they start from the same place at the same time and walk in opposite directions, they meet every two minutes; if they walk in the same direction, they meet every six minutes. It is known that Party A runs faster than Party B, how many laps do Party A and Party B run in each minute?
2. One A-type steel plate can be used to make two C-type steel plates and one D-type steel plate; one B-type steel plate can be used to make one C-type steel plate and two D-type steel plates. Now 15 C-type steel plates and 18 D-type steel plates are needed. A-type steel plate can be used exactly. How many B-type steel plates?
3. Take a spring and make it hang 2kg object, the length is 16.4cm; hang 5kg object, the length is 17.9cm. How long should the spring take? (hint: to use the relationship between the mass of the spring hanging object and the length of the spring extension, M = K (l-lo), where Lo is the length of the spring without hanging object, K is a constant, M is the mass of the spring hanging object, and l is the length of the spring hanging 5kg object.)
The problem expired after 20:00 on April 19, 2009! Because these questions give me the correct solution. Because there's no equivalent relationship. If it's right, you can add it!

1. A and B run on the circular road at the same speed. If they start from the same place at the same time and run in opposite directions, they meet every two minutes. If they run in the same direction, they meet every six minutes. It is known that a runs faster than B, how many laps does a and B run in each minute? Suppose a runs x laps in each minute and B runs y laps in each minute, then 2x + 2Y = 1 6x-6y = 1

1. The route from city a to city B is 1200 km long. It takes 2 hours and 30 minutes for an aircraft to fly from city a downwind to city B, and 3 hours and 20 minutes for an aircraft to fly from city B upwind to city A. The average speed and wind speed of the aircraft can be calculated
2. Each tin can be made into 25 tin bodies or 40 tin bottoms. One tin body and two tin bottoms form a set of tin. There are 36 tin sheets. How many tin bottoms can make the tin body and the tin bottoms match each other?
3. There is a section of uphill and a section of level road from a to B. if the uphill speed is 3km per hour, the level road speed is 4km per hour, and the downhill speed is 5km per hour, then it takes 54 minutes to go from a to B and 42 minutes to go from B to a. what is the total distance from a to B?
Once again, we use the solution of the quadratic equation of two variables,

1. Let the wind speed be y, and the average speed of the aircraft be x, then the equation: (x + y) * 5 / 2 = 1200 (X-Y) * 10 / 3 = 1200) can be changed into x = 480-y generation equation 2 by substitution method, and the solution is y = 60, and the original equation of y = 60 generation is x = 420. Therefore, the average speed of the aircraft is 420km / h, and the wind speed is 60km / H.2