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A math problem, urgent answer! I don't understand Given that P is a point outside the line L, take P as an end point to make a line segment PQ, so that the end point q is on the line L, and the length of the line segment PQ is 5cm. The number of such line segments can be made is () A. 0 or 1 B.1 or 2 c.0 or 2 d I chose B, but it's wrong. Please tell me the correct answer and reason
It should be 0, 1, 2
If the vertical distance from P to the line is greater than 5cm, then the line segment PQ = 5 cannot be made, so the number of lines is 0
If the vertical distance from P to the line is equal to 5cm, then only one line segment PQ = 5 can be made, so the number of lines is 1
If the vertical distance from P to the straight line is less than 5cm, two segments can be made, PQ = 5, so the number of segments is 2
So you can only choose D
There's a math problem that I don't understand,
In May, the TV factory produced a batch of TVs. The number of TVs in the first ten days accounted for 3 / 11 of the total. In the second ten days, it produced one fifth more than that in the middle ten days, which was exactly 40. How many TVs did the factory produce in May?
In the first ten days of the year, the number of units accounted for 3 / 11 of the total,
1-3 / 11 = 8 / 11, [8 / 11]
The production in the second ten days is one fifth more than that in the middle ten days, which is exactly 40 sets. The production in the middle ten days is 40 △ 1 / 5 = 200 sets;
Output in the last ten days = 200X (1 + 1 / 5) = 240 (sets);
Total TV production in May = (200 + 240) △ 8 / 11 = 605 (sets)
Several mathematical problems (Concepts)
1. All even numbers are expressed as__________
2. All odd numbers are expressed as__________
The following statement is correct_______ (not necessarily single choice)
A. The sum of rational numbers is rational numbers B. the sum of irrational numbers is irrational numbers
C. Real numbers are decimals D. rational numbers can be written as fractions
The positive divisor of 4.16 is__________
5.2x ^ 2-2 (radical 3 + radical 2) x + radical 6_________
6. (x + 1) ^ 3 - (x-1) ^ 3 the result of factorization is______________
2n, n belongs to Z
2n + 1, n belongs to Z
BD
1 2 4 8
Multiplication by Cross (2x radical 3) (x radical 2)
Merge after expansion: 2 (3x ^ 2 + 1)
Li Yun was in a train with a speed of 60 kilometers per hour by the window. He saw a truck with 30 carriages coming. When the front of the truck passed the window, he began to count the time until the last carriage passed the window. The time recorded was 18 seconds. It is known that the length of the truck carriage is 15.8 meters, the distance between the carriages is 1.2 meters, and the length of the truck head is 10 meters. What is the speed of the truck?
I would like to ask if there is a distance between the front of the car and the first car? If so, do you want to calculate this distance?
I don't need you to say the answer to this question. I'll do it myself
I know it's 29 spaces. I asked if there is a gap between the front of the car and the first section
You are serious and comprehensive, which is worthy of praise
1. According to the title, "carriage spacing" literally means the distance between "carriage" and "carriage". Combined with the different lengths of "carriage" and "vehicle head", I think "carriage spacing" is not the distance between "carriage" and "vehicle head"
2. There should be no distance between the front of the car and the first carriage
In fact, you take these into account, the answer does not matter
Concept judgment of mathematical problems
-0.3 is negative, but it is not rational
0.5 is a decimal, so it is not a rational number
They are all rational numbers
7e=4e+____ What's on the line
Primary school, do you have a score? Do you have division? I can only give 3 / m, that is, 3 / m
1. A businessman in city a has a donkey and 3000 carrots. If he wants to take carrots to city B 1000 kilometers away, he can only carry them on his back. It is known that the donkey can carry 1000 carrots at a time, but he has to eat one carrot every kilometer. How many carrots can the businessman sell? (does the donkey eat carrots? This is a Korean intelligence problem.)
2. 1,3,12,40,) guess what the fifth number is?
3. There is a fork in the road, there are two roads. One is a living road, and the other is a dead road. There are two people at the intersection, one is telling the truth, the other is lying. You can ask each of them a question, but their answer can only be "yes" or "no". So you can judge which is the living road
1.
This is the answer I got from my search
The first time, of course, was to walk 200 kilometers. After three rounds, 2000 donkeys were laid down. The second time, at 553 + 1 / 3 kilometers, 334 donkeys were laid down and 333 donkeys were taken back. When the donkey returned to 200 kilometers, it finished eating these 333 donkeys, but it still walked 2 / 3 kilometers more. However, it didn't need feeding in less than 1 km. This is to take the remaining 1000 donkeys and eat 333 donkeys in 553 + 1 / 3 kilometers. At the same time, it walked 2 / 3 kilometers more, At this time, if you go 1 / 6 kilometer further, you will come back 1 / 6 kilometer. If you gather 1 kilometer, you will eat one. Then you will take 334 which you put down last time and gather 1000. Finally, you will take the 1000 to go out from 533 + 1 / 3 kilometer. The rest of the way is 466 + 2 / 3 kilometer, but you only need to eat 466, If the donkey wants more radishes, it will kill the donkey. The donkey doesn't care about walking 2 / 3 kilometers more, so there are 534 left
2.1 = 0 ^ 2 + 1 (^ 2 for square)
3 = 1^2+2
12= 3^2+3
40= 6^2+4
=10^2+5
（3=2×3/2；6=3×4/2；10=4×5/2）
So the fifth number is 105
It's hard to think of it. It's absolutely original
I have seen this question
Casually find one of them, point to one of them and ask him: if I go to ask another, will the other tell me that this road is a way to live?
If he answers "yes", the other way is to live
If he answers "no", then this is the way to live
(please note that the answer you get ("yes" or "no") is only related to the road you are pointing to, not to the person you are asking. As long as you are pointing to the living road, the answer you get must be "no")
It's a difficult question to talk about. I hope you can understand me
Hope to help you!
Given that C / (a-b) = A / (B-C) = B / (A-C) = k, a, B, C are positive numbers, then the function y = - KX must pass through which of the following points ()
A.(1,1/2)
B.(1,-1/2)
C.(1,2)
D,(1,-1)
A wooden stick is 10 cm long and rotates around its center to form a circle. The circumference of the circle is () cm
There is a thick column in the hall of Chunguang hotel. It is measured that its circumference is 6.28 meters and its diameter is () meters
A bridge is 2500 meters long, and the diameter of a car's wheel is 80 cm. If the car's wheel rolls 200 circles per minute, how many minutes will it take for the car to cross the bridge
【1】
2*3.14*(10/2)=31.4(cm)
The circumference of this circle is 31.4cm
【2】
The diameter of this column = 6.28 / 3.14 = 2m
【3】
80 * 3.14 = 251.2 cm
251.2 * 200 = 50240 cm = 502.4 M
2500 / 502.4 = 5 minutes
There is a natural number, divided by 2 to 1, divided by 3 to 2, divided by 4 to 3, divided by 5 to 4, divided by 6 to 5, the minimum number is ()
Obviously, it is the common multiple of 2, 3, 4, 5 and 6 - 1, so the least common multiple is 60, which is 59
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