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Is it possible to catch up with the time when the common distance △ speed difference?
no
Catch up time = distance difference △ speed difference
It's a bad journey, not a common journey
Xiaoqiang walks for 16 minutes at the speed of 5km / h, and then Xiaoming pursues Xiaoqiang at the speed of 13km / h. The time from starting to catching up with Xiaoqiang is ()
A. 16 hours B. 10 hours C. 8013 hours D. none of the above is true
Let Xiaoming's time from starting to catching up with Xiaoqiang be x, then 5 (x + 1660) = 13X and the solution is x = 16
On the function expression of mathematics
At a certain time, the ground temperature of Yiyang is 20 ℃, and the temperature at the place x km above the ground is y ℃. The functional relationship between Y and X is written and solved
Y=20-6X
It is known that f (x) is a linear function and satisfies f (x + 1) = 2x + 7
Let f (x) = ax + B, then f (x + 1) = ax + A + B ∵ f (x + 1) = 2x + 7 ∵ a = 2A + B = 5. The solution is a = 2B = 5 ∵ f (x) = 2x + 5, so f (x) = 2x + 5
Mathematics, function expression
It is known that the maximum value of square + 25 of quadratic function y = a (x-0.5) is 25, and the cubic sum of square + 25 = 0 of equation a (x-0.5) is 19?
The quadratic function has the maximum value, so a
What is the function expression of straight line in mathematics
y=kx+b
y=kx
Is a mathematical expression a function
Mathematical expression and function are completely two concepts. Mathematical expression is a simple formula, and function is a rule of independent variable corresponding to dependent variable. Some functions can have mathematical expression (that is, this corresponding rule can be written as mathematical expression), while others do not
For example, Pythagorean Theorem A & # 178; + B & # 178; = C & # 178;, if you think that two right angles of a right triangle can be changed at will, then the length of the hypotenuse will be changed because of the change of the two right angles, and it will be understood as a function. The independent variables are a and B, and the dependent variables are C
1. The engineering team can build a highway and work 6 hours and 12 days a day. If the work efficiency remains the same, how many days can it work 8 small things a day?
2. It takes 10.6 hours for China's scientific experimental satellite to orbit the earth in the air for 6 cycles, and how many hours for 14 cycles?
three
A saltern can produce 3G salt with 100g seawater. According to this calculation, if 585000 tons of seawater are put into a saltern at a time, how many tons of salt can be produced? How many tons of seawater can produce 9 tons of salt?
1. Assume a day to complete
6x12=ax8
A = 9 days
2. Suppose it takes a hour
10.6/6=a/14
A = 24.733 hours
3. Suppose that a ton of sea water and B ton of sea water are exposed to the sun and 9 tons of salt are exposed to the sun
100/3=585000/a
a=17550
100/3=b/9
b=300
What details should be paid attention to in addition to three, four, five, six paragraphs in the pursuit of perfect paintings in Suzhou gardens
In paragraph 7.8.9, the beauty of composition in every corner, the beauty of design in doors and windows, and the beauty of color in architecture are explained in detail
What is the unit of work efficiency?
Work efficiency is generally a fraction, unit is also a fraction form, denominator is a unit time, such as: every year, every month, every day, every hour, every minute, every second. The unit of numerator is the unit of total workload
Primary school is not so complicated
Primary school work efficiency is understood and used in accordance with the unit
RELATED INFORMATIONS
- 1. 5 / 6 of a's work efficiency is equivalent to B's work efficiency. Here, the work of () is regarded as unit 1, and the work efficiency of () accounts for 5 / 6?
- 2. To harvest a piece of wheat, it takes 8 hours for a to finish harvesting, and the working efficiency of B is 80% of that of A How many more hours will it take to finish harvesting this piece of wheat?
- 3. How to find the percentage of a number? Can frequency be regarded as the percentage?
- 4. An object begins to slide on the ice surface at a speed of 10m / s, and decelerates evenly. After sliding for 10m, the object stops, so it takes a lot of time for the object to slide for 6m______ S (root is allowed)
- 5. The basic process of solving practical problems with linear equation of one variable generally includes setting, listing and checking, that is (), (), (), (), (), () It's the basis of a series of equations
- 6. Party A and Party B cooperate to complete a work. Due to good cooperation, the work efficiency of Party A is 1 / 10 higher than that of Party A alone, and that of Party B is 1 / 5 higher than that of Party B alone, Party A and Party B work together for 4 hours, completing two fifths of the whole work. The next day, Party B works alone for 4 hours, leaving 13 / 30 of the work unfinished. How many hours does it take for Party A to complete the work alone? Give me a reply in 12 hours!
- 7. (1) It takes 10 days for a job to be completed by Party A alone. If Party A and Party B work together, it takes 6 days. This job will be completed by Party A and Party B after 2 days, and the rest will be completed by Party B alone. How many days does Party B need to work? (2) there is a batch of grain in the warehouse, 2 / 3 of which is less than 1 ton. At this time, the ratio of the remaining grain to the total grain is 3:5?
- 8. The C language expression equivalent to integral mathematical expression AB / (a + b) is
- 9. In a math activity class, Mr. Li led the students to measure the height of the teaching building. In the sunlight, the shadow length Ba of Huang Li's BC, who is 1.65 meters tall, is 1.1 meters. At the same time, the shadow length DF of the teaching building De is 12.1 meters. (1) please draw the projection DF of the teaching building de in the sunlight. (2) please calculate the height of the teaching building de according to the measured data (accurate to 0.1M)
- 10. Virtual module length, how to find ah. Use mathematical expressions bar
- 11. The distance between the two when catching up___________ =The distance between the two at departure
- 12. The express and local trains leave from both places at the same time. The express trains travel 33 kilometers per hour. The meeting is four seventh of the whole journey. It is known that it takes 8 hours for the local train to complete the whole journey
- 13. The formula of sum difference multiple problem,
- 14. What is the length of a circle
- 15. Calculation formula of stirrup length in column
- 16. What is the difference between the waist bar (structural bar) and the torsion bar in the beam
- 17. There may be a formula for calculating the length of spiral reinforcement in pile foundation? For example, the length of spiral reinforcement is Φ 10@12 The diameter of reinforcement cage is 108.4
- 18. How to draw a 400 meter long runway on a 200 meter long and 100 meter wide playground? Draw a nine line diagram
- 19. As shown in the picture, there is a 300 meter small track in the 400 meter track of the school playground. The distance between the large track and the small track is 200 meters. A runs counter clockwise along the large track at the speed of 6 meters per second, and B runs clockwise along the small track at the speed of 4 meters per second. The two start from the intersection a of the two runways at the same time. When they meet on the runway for the second time, how many meters did a run?
- 20. If the curve of the standard 400m runway is semicircle, and the radius of the innermost curve is 36m, and each runway is 1.2 wide, there are six runways 1. What is the radius of the semicircle runway on the outer circle? 2. How many meters ahead of the starting point of the first runner in the 200 meter race? 3. How many meters ahead of the starting point of the third runner in the 400 meter race? 4. If the 400 meter race is still in progress, how many meters ahead of the first runner is the fifth runner?