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Use equations to solve application problems 1. When a ship sails between two docks, it takes 4 hours to sail downstream and 5 hours to sail upstream. The current speed is 1 hour and 1 kilometer. What is the sailing speed of the ship in downstream and upstream? 2. When a ship sails between a and B, it takes 8 hours to go with the water and 10 hours to go against the water, and the known water speed is 2 km / h 3. A construction site needs to send 48 people to excavate and transport soil. If each person excavates 5 cubic meters of soil or transports 3 cubic meters of soil, how to arrange the personnel to make the excavated soil be transported in time? 4. Each tin sheet can be used to make 25 tin bodies or 40 tin bottoms. One tin body and two tin bottoms form a set. At present, there are 36 tin sheets. How many tin bodies and tin bottoms can be used to make the tin body and tin bottoms match each other? 5. A square table consists of one table top and four legs. If one cubic meter of wood can be used to make 50 or 300 legs on the table top of the square table, and there are 5 cubic meters of wood, how many cubic meters of wood can be used to make the table top and legs, and how many legs can be made into the square table?
1, assuming the normal speed is x km / h
4(x+1)=5(x-1)
x=9
The sailing speed of the ship is 10km / h and 8km / h respectively in downstream and upstream
2. Suppose the distance between the two places is x km
x/8-x/10=2*2
x=160
3. Assuming x for the box body, 36-x for the box bottom
2*25x=40(36-x)
50x=1440-40x
x=16
Use 16 box making bodies and 20 box making bottoms
4. Assuming x cubic meters of wood is used as the table top, the leg is 5-x cubic meters
4*50x=300(5-x)
200x=1500-300x
X = 3 cubic meters
5-3 = 2 M3
X * 50 = 150
Use 3 cubic meters of wood to make the table top and 3 cubic meters to make the table legs. The table legs just match the square table, which can match 150 meters
Use simple equations to solve the following practical problems
1. One set of books costs 2.5 yuan per book, and the other set costs 3 yuan per book. They bought two sets each, and spent 22 yuan in total. How many copies of each set?
2. Bought 20 kg rice and 105 kg noodles one by one, paid 45.6 yuan in total, 2.1 yuan per kg for giant salamander, how many yuan per kg for noodles?
3. One by one, buy 10 books and 3 pens, a total of 10.8 yuan, 0.24 yuan, how many pens?
（1）
Set X books for each series and set up equations
2.5x+3x=22/2
5.5x=11
x=2
（2）
Let x yuan per kilogram of noodles, set up the equation
20*2.1+105x=45.6
105x=3.6
X = it doesn't make sense
（3）
Let each pen have X elements and set up the equation
10*0.24+3x=10.8
3x=8.4
x=2.8
The application problem is a little simpler
For a project, it takes 6 days for Party A to do it alone, and 10 hours for Party B to do it alone. If Party A, Party B, Party A and Party B work alternately, one hour at a time, how long does it take? For a project, it takes 6 hours for Party a to do it alone, and 10 hours for Party B to do it alone
RELATED INFORMATIONS
- 1. There is a practical problem. It's actually very simple. It's about engineering problems The efficiency of team a is 3 / 5 of that of team B. the two teams can complete 2 / 3 of this section of road in 6 days. The rest will be completed by team B alone. How many days will it take to complete it?
- 2. It's a simple one On January 22, 2010, Mr. Zhang, a shareholder, bought 1000 shares of a certain stock at the price of 16.32 yuan. On January 25, the price of the stock rose by 1 / 10. However, the stock market changed dramatically. On January 26, the price of the stock fell by 1 / 10. Mr. Zhang said that my stock price was the same as that on January 22. Is Mr. Zhang right? Calculation instructions
- 3. Party A and Party B go from place a to place B at the same time. Party A walks 250 meters per minute and Party B walks 90 meters per minute. After arriving at place B, Party A immediately returns to place a and meets at 3.2 kilometers away from place B. what is the distance between two places? Explain why
- 4. For a three digit number, now move the leftmost number to the rightmost one, which is 45 times smaller than the original number. It is also known that 9 times of a hundred digit number is 3 times smaller than the two digit number composed of ten digits and one digit number, so as to find the original three digit number Solving the first order equation with two variables
- 5. On a mathematical calculation problem Bank interest calculation question: withdraw 5000 yuan, and the daily interest is 0.05% [for example, one day is 2.5 yuan, and the next day is (5000 + 2.5) * 0.0005]. Ask 31 days, how much is the interest? Again, if I return 100 yuan every month for 31 days, how many months can I repay all the money? Similarly, the remaining 100 yuan is still calculated according to the daily interest of 0.05%!
- 6. Love primary school bought 12 desks and 16 chairs to donate to teachers in Yingjiang, Yunnan Province. The total cost of desks and chairs was 3150 yuan. Each chair is 70 yuan cheaper than each desk. How much is each desk and chair?
- 7. Primary school mathematics problem-solving steps and methods, to be detailed!
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- 9. The deduction standard of junior high school mathematics fraction application questions The number given in the original question is 1.25. How many points can I give to my whole fractional equation according to the 1.5 column?
- 10. 1. A project! Team a will do it alone, and it will be completed within the specified date! If team B will do it alone, it will take more than 3 days. Now team B will do it alone two days later, and it will be completed within the specified date! Question: what is the specified date? 2. Make a new coating with 100 yuan a coating and 240 yuan B coating! The total value remains unchanged! The new coating is sold 3 yuan less per kilogram than a coating and 1 yuan more than B coating per kilogram! What's the price of this new coating? Drought is coming! A middle school donated 1800 yuan to class a of Grade 8, and 1560 yuan to class B. It is known that class A is 1.2 times the average donation of class B, and class B has 2 more people than Class A. how many people are there in each class?
- 11. 1. In the physical education class of class 501, there are 34 people participating in rope skipping activities. They should be divided into five groups, at least how many more people? How many groups can they be divided into?
- 12. Several simple practical questions 1. Make a batch of small farm tools. The first workshop can process 50 pieces a day. If the second workshop does it for 10 days, it can complete the task. Now the two workshops cooperate. When this batch of tasks are completed, the second workshop has completed 80% of the total number of small farm tools 2. Party A and Party B respectively accept the same number of freight transportation tasks. After 14 days of joint transportation, team a has 64 tons left and team B has 484 tons left. It is known that the working efficiency of team B is 60% of that of team A. how many tons does team a transport every day? 3. The grain store transported 260 bags of rice and flour. After selling one twelfth of the rice, the remaining rice was 7 bags less than flour. How many bags of rice were transported in?
- 13. To solve practical problems, The boys like the modei car 2. Are these your books Please put the boxes here 4. They go to school [at seven thirty] Practical questions 1. Xiaowei has 30 2-cent and 5-cent coins in the storage tank, which are worth 9.9 cents in total. How many coins are there in each of them? 2. Master Zhang carries 1000 glass bottles. It is stipulated that he can get 0.3 yuan for carrying one bottle, but he will not pay 0.5 yuan for breaking one bottle. After transportation, Master Zhang actually gets 260 yuan for carrying one bottle?
- 14. In the spring of 2009, influenza A (H1N1) virus spread in the United States and some other countries, and human beings had another battle with the virus. Peracetic acid is one of the disinfectants that can effectively kill avian influenza virus. 0.2% Peracetic acid solution is often used for air and ground disinfection. A farm needs to prepare 50 kg of 0.2% Peracetic acid disinfection solution, How many kilograms of 10% Peracetic acid solution is needed? How many kilograms of water should be added? Answer before 9 o'clock
- 15. A few simple practical problems Party A and Party B work together to make a batch of parts. It takes 12 days for Party A to do it alone, and 8 days for Party B to do it alone. After 6 days for Party B to do it alone, Party A will do the rest of the tasks alone. How many days will it take to complete the task?
- 16. Several simple practical problems On the drawing with a scale of 1:80, the length of the house is 10 cm and the width is 9 cm. How many square meters of tiles should I buy to lay tiles on the floor of the house?
- 17. There is a distance of 160km between a and B. three hours after a long-distance bus leaves from a, a car also leaves from A. as a result, the car arrives at B 20 minutes later than the long-distance bus. It is known that the speed of the car is three times that of the long-distance bus. The speed of the two cars is calculated
- 18. Application of solving fractional equation A 20km wide shelterbelt has been built in a county, so that the average height of sand passing through the shelterbelt is reduced by 50%, and the time of sand passing through the same distance is increased by 20 minutes. What is the height of sand before it reaches the shelterbelt? Let's solve it
- 19. If the numerator of a fraction is reduced by 10% and the denominator is increased by 50%, the percentage of the decrease of the new fraction is 10%______ ．
- 20. The sum of the numerator and denominator is 30. After the denominator is increased by 22, a new fraction is obtained. This fraction is reduced to one third of the simplest fraction. What is the original fraction? Better not use the equation