![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
On practical problems and engineering problems of linear equation with one variable! 1. A pool has two taps, a and B. a single tap can fill the empty pool in 2 hours, and a single tap can fill the empty pool in 3 hours. Now turn on the tap first, and then turn on both taps half an hour later. How many hours does it take to fill 2 / 3 of the total volume of the pool 2. There are three water pipes a, B and C in a pool. A and B are the inlet pipe and C is the drainage pipe. The pool can be filled in 16 minutes by opening pipe a, 10 minutes by opening pipe B, and 20 minutes by opening pipe C. now open pipe a and B first, and close pipe a after 4 minutes C pipe, ask again after a few minutes to fill the pool I hope it's faster and more accurate I'll wait online
one
It takes a total of X hours
1/2*1/2+(1/2+1/3)*X=2/3
X=1/2
two
Let's fill it up again in X minutes
(1/16+1/10)*4+(1/10-1/20)*X=1
x=7
Don't you understand my answer?
The law of the profit and loss problem in the practical problem of the first grade mathematics of junior high school
Quantitative relationship
Type of one profit and one loss: shares = (profit + loss) × two distribution differences
Double profit type: number of shares = (large profit small profit) × twice distribution difference
Double deficit type; number of shares = (big deficit small deficit) × twice distribution difference
(2) Total quantity = number of points per time × number of copies + profit
Total quantity = number of points per time × number of copies - deficit
The first problem of mathematics in junior high school: practical problem and linear equation of one variable -- travel problem
According to information records, the B2 bomber developed by the United States flies at a speed of 1540 km / h in the downwind and 1260 km / h in the upwind. When it is full of fuel, it can fly continuously for 10 hours. After each mission, it must leave enough time to return to the base, or it will crash on the way
(1) With the above information, what is your estimation of the farthest attack distance when it starts downwind
(2) If it starts against the wind, will the maximum attack distance change? Why?
Let's set the farthest downwind travel for X hours, and get 1540 x = 1260 * (10-x) and x = 4.5, so the farthest running distance is 1540 * 4.5 = 6930 km (2) No. because it's downwind when we go, then it's downwind when we come back. Let's set the farthest downwind travel for X hours, and get 1260 x = 1540 * (1
What's the word "don't care about things, although you often see them, it's the same as not seeing them"
Turn a blind eye to
The difference between the numerator and denominator of a fraction is 3. If the numerator and denominator are added with 13 at the same time, it can be reduced to the simplest fraction 6 / 7 and the original fraction can be obtained?
I hope you will pay more attention
Let the numerator be x and the denominator be y
Since the reduced fraction is less than 1, X
Are open syllables and closed syllables for monosyllabic words?
I see the examples in the book are monosyllabic words
If it doesn't refer to monosyllabic, please give me a few examples to prove it
Open syllable and closed syllable are a group of concepts. Monosyllabic, disyllabic and polysyllabic are also a group of concepts. English words have one syllable, two syllables and many syllables. One syllable is monosyllabic, two syllables are disyllabic and more than three syllables are polysyllabic, Let's see whether these syllables are open syllables or closed syllables. So it's not open syllables. Closed syllables are not equivalent to monosyllabic words. For example, potato is composed of three syllables, and all three syllables are open syllables. The examples in the book are monosyllabic words, because monosyllabic words are the simplest
3A translation of unit 14, grade 9
Go for it unit 14 3A translation online, etc
Give me a bonus
Hi Jake, I'm sorry I can't get back to you right away. I have a lot of housework to do today. Of course, I have to do my homework. I started an hour ago, but I haven't finished it yet. Then I have to walk my dog, water my mother's flowers and go shopping. I haven't finished those things yet. Because my grandfather comes to talk to me. He likes to talk to me, He began to tell me all the things he had to do when he was a child. He had to get up at 5 o'clock to cut wood and cook. Then he had to draw water from the well and feed animals. He said he and his family lived on the farm
Anyway, I need to do it quickly
Take care of it,
CRYSTAL
Simplification 1) BC + AB 2) BD + CD + BC 3) AB + DF + CD + BC + fa
BC+AB=(A+C)B BD+CD+BC=(B+C)D+BC AB+DF+CD+BC+FA=D(F+C)+B(A+C)+FA
Exercises on trigonometric functions
Given a trigonometric function y = √ 2Sin (π / 8x + π / 4), how can we find the analytic expression of the new function with x = 8 symmetry?
Why?
Any point (x, y) on a symmetric curve must be on a known curve
The coordinates of the point (x, y) with respect to the line x = 8 are (16-x, y),
By substituting the point (16-x, y) into the known curve y = √ 2Sin (π / 8x + π / 4), we can get the following results:
y=√2sin(π／8(16-x)+π／4）
That is y = √ 2Sin (2 π - π / 8x + π / 4)
Y = √ 2Sin (- π / 8x + π / 4), which is the equation of the symmetry curve
The pronunciation of "Daoxing" in the latest edition of dictionary
Pinyin: D à o · h é ng
RELATED INFORMATIONS
- 1. If the price of type I refrigerator is 2298 yuan per unit and that of type II refrigerator is 1999 yuan per unit, according to the relevant policy of "home appliances to the countryside", the government subsidizes the farmers who buy refrigerators at 13% of the price of each refrigerator. Q: how many yuan has the government subsidized the 1228 type I refrigerators and type II refrigerators sold to the farmers in the first month after the launch of the activity (2 valid figures are reserved)?
- 2. As shown in the figure, the inner bottom radius of a cylindrical glass container containing water is 10 cm, and the height of water in the original container is 12 cm. After a glass rod with a radius of 2 cm is vertically inserted into the water, how many cm will the water in the container rise? (volume of cylinder = bottom area × height)
- 3. Huanggang 100 points to break through the mathematics seventh grade |What is the answer to 1 / 2-1 | + | 1 / 3-1 / 2 | + | 1 / 4-1 / 3 | + | 1 / 5-1 / 4 | +... + + 1 / 100-1 / 99 |?
- 4. All answers to the new observation of mathematics in Grade Seven
- 5. All the answers of the seventh grade mathematics new observation people's education press in the next semester
- 6. For example: 3x / 2 = 5x / 6, the least common multiple of the denominator is 6, so does 5x / 6 multiply by 6?
- 7. I want to ask how to find the least common multiple when the first-order equation with one variable in grade seven goes to the denominator step by step Such as the title
- 8. Divide 99 into four numbers, so that the first number plus 2, the second number minus 2, the third number multiplied by 2, the fourth number divided by 2, the results are equal. How do you think we should divide 99 into four numbers?
- 9. Mathematics Grade 8 Volume 1 p27 question 10
- 10. Zhejiang Education Press seventh grade mathematics homework review questions
- 11. The afforestation activity of "protecting mother river" has been carried out in a city. Jinqiao village has 1 & nbsp; 000 mu of wasteland, the greening rate is 80%, 300 mu of good land is regarded as greening, and the greening rate of river slope has reached 20%. At present, the greening rate of all the land in Jinqiao village is 60%. How many mu of river slope is there
- 12. A series of linear equations with one variable An individual taxi driver is required to pay 1400 yuan per month and 0.5 yuan per kilometer for gasoline; another state-owned taxi company is required to pay 1.2 yuan per kilometer for gasoline without salary (1) If the unit runs an average of a kilometer per month, how much will each of the two car rental schemes cost? (2) Please design a plan for the unit, so that the unit can choose a reasonable way to rent a car
- 13. Who can give me a few one variable equation problems It is difficult and not practical
- 14. How to make linear equation with one variable? Use an example to analyze,
- 15. Solving engineering problems with linear equation of one variable To build a road, it takes 3 days for team a to do it alone, and 7 days for team B to do it alone. If team a and team B construct from both ends at the same time, how many days will it take to dig a good canal?
- 16. Engineering problems of linear equation with one variable To process a batch of parts, workers a need 15 hours, workers B need 20 hours, and workers C need 10 hours. Now, workers a and B process 5 hours at the same time, and then workers C do it alone. How many more hours to complete!
- 17. Linear equation of one variable There are 48 barrels of water in the two tanks. Tank a adds twice as much water to tank B, and then tank B adds the remaining half of tank a to tank A. then the water in the two tanks is equal. How many barrels are there in the first two tanks?
- 18. The first volume of the first year of junior high school is a problem of solving practical problems with linear equation of one variable In the 22 rounds of the Super League, a team scores 27 points. The ratio of the number of draws and losses is 2:3. Find the number of wins of the team
- 19. The film crew had a day's journey from city a to city B. they planned to walk 100 kilometers more in the morning than in the afternoon to have lunch in city C. due to the traffic jam, they arrived at a small town at noon and drove only one third of the original plan. After passing the town, the car drove 400 kilometers and stopped in the evening to have a rest. The driver said that one third of the journey from City C to here would reach the destination How many kilometers away?
- 20. The first order equation of one variable, The two ports of AB are 300 km apart. If ship a goes downstream from a to B, and ship B goes from B to a at the same time, the two ships meet at C. If ship B goes downstream from a to B, and ship a goes from B to a at the same time, the two ships meet at D. It is known that the distance between two places of CD is 30 km, and the speed of ship a is 27 km / h,