A fourth grade math problem, I don t know, ask for advice

Solution: Let the same length be x, then:

236-x=4×（176-x）

236-x=704-4x

3x=468

x=156 Now the long rope has: 236-156 = 80 (m) and the short rope has: 176-156 = 20 (m).

A: Now the long rope has 80 meters and the short rope has 20 meters.

The difference of the rope does not change.

Now the length of the short rope: (236-176) (4-1) = 20 meters.

Now the length of the long rope: 20 4 = 80 meters.

Set: The length of each of the two ropes is x

Then: (236-x) (176-x)=4

236-x=176*4-4x

3x=704-236

The current length of the x=156 long rope is: 236-156=80 (m) and the current length of the short rope is: 176-156=20 (m).

Solution: Set to go x meters.

From the meaning of the title. 236-x) (176-x)=4 gives x=156

Long rope = 236-156 = 80 (m).

Short rope = 176-156 = 20 (m).

Let the one that goes is x

236-x=4（176-x）

236-x=704-4x

3x=706-236

3x=468

x=156 then: the long one is now 80m, and the short one is now 20m.

Let go x meters, then.

236－x=4×(176－x)

The solution is x=156

Now: 20m, 80m

Next to the brush, first brush the first piece, then brush the second piece for the first time, and then brush the third piece for the first time, at this time the first piece has been dried, and then start from the first piece double and second times, all three brushes take a total of 3 3 2 = 18 minutes; If you add the last piece to dry, the time is 22 minutes.

Brush next to each other, don't need to take out time to dry alone, keep brushing, a total of 3 3 2 = 18 minutes.

Brush the first block for 3 minutes, brush the second block for 3 minutes, then 2 dry the first piece, brush the third block for 3 minutes, the first piece is dry, the second piece is also half dry, and so on

6x3 = 18 minutes.

3+4+3=10 (minutes).

10 + 6 + 2 = 18 (minutes).

A: It takes as little as 18 minutes.

There is a trick to this problem: you don't need to do it yourself to dry, and you have to do it yourself to brush the board, so . The time it takes to brush the planks is the answer.

This question is really not nutritious, and no matter how you brush it, you have to brush it 6 times.

There is no time gap.

So no matter how you brush, it's 6 x 3 = 18 minutes.

18 minutes. After the first brushing, the three boards of ABC drying time are; Therefore, you don't have to wait for the second time to brush the board A, and the drying time of the three boards after brushing A is respectively; There is no need to wait for the second time to brush B, and the drying time of the three boards after brushing B is ; So you don't have to wait for the second time to brush C, the whole process takes 18 minutes, which is the time to brush each board, can you understand?

3 2 3 = 18 (minutes).

Brush the 3 pieces for the first time in turn, and after brushing the third block, the first piece has already passed the drying time, and then brush it from the first piece in turn.

18 minutes.

1.Brush the first block for the first time for 3 minutes, brush the second block for the first time for 3 minutes, then brush the first block for the second time for 3 minutes, then brush the third block for the first time for 3 minutes, then brush the second block for the second time for 3 minutes, and finally the third block for the second time for 3 minutes.

2.Brush the 3 pieces one after the other for the first time. Brush it again from the first block.

Brushing takes 3x3x2=18 points.

It takes 3x4 = 12 points to dry.

Because you can brush it when you are drying.

So 18 points are required.

It takes 3 minutes to brush the first block, then the second piece, it takes 3 minutes, and then the third piece, it takes 3 minutes, so that the first piece is left to dry for 6 minutes, and you can brush the second time, and the second time is also used to brush the first block, which takes 3 minutes, and then the second block, which takes 3 minutes, and then the third piece, which takes 3 minutes, so it takes 18 minutes in total.

Answer: The idea is as follows: make sure that the painter keeps brushing the plank without stopping and it takes the shortest time, eh. They all spoke out.

The first plate The second plate The third plate Column: 6 times 3 equals 18 for the first time.

The second time positive.

The third time is positive.

The fourth anti.

The fifth anti.

Sixth anti.

Brush the first piece first, a total of 3 * 2 = 6 minutes, and then take it to dry, dry the first piece at the same time to brush the second piece, the second piece is also 6 minutes, that is to say, the second piece only needs 6-4 = 2 minutes, plus 4 minutes to dry, the first and second blocks take a total of 12 minutes, and then the second piece is dried, and the third piece is brushed at the same time as drying, it takes 2 * 3 = 6 minutes, a total of 12 + 6 = 18 minutes.

Press.

Brush the first time in the order of one, two, and three. Then brush the second pass in order (6 minutes after the first pass of the first block). That is, 3+3+3+3+3+3+3=18 (minutes).

6 bunting is divided into.

The number of segments (intervals): divided into 5 segments, with a difference between the beginning and the end, and 4 inserted in the middle, so the length of each segment (interval) of the 5 segments; The length of a section is 15 5 = 3 (meters) The number of sections (intervals) that the corridor of the office building can be divided into: 27 divided by 3 = 9 (paragraphs) How many colored flags should be inserted in the corridor of the office building:

9 paragraphs and 9 pieces, counting the first one, there are a total of 9 + 1 = 10 (pieces).

The corridor is divided into 5 sections, each with a length of 3 meters.

Based on this calculation, the corridor of 27 meters is also one at the head and one at the end, each section is 3 meters, and it will be divided into 9 sections, and 10 colored flags will be planted.

The number of segments (intervals) into which the 6 bunting is divided: 6-1=5

The length of each segment (interval): 15 3 = 5

The number of sections (intervals) that can be divided into office building corridors: 27 3 = 9 How many colored flags should be planted in the office building corridor: 9 + 1 = 10

Analysis: The parallel line bai is a straight line, which is infinitely long, and there is no length or shortness, so the length of the two parallel lines is 5mm

There are only three possibilities:

First: There is a problem with the title of the question, and only one of 2cm and 5mm can be kept.

Second: the distance between these two parallel lines is 2cm+5mm, that is, 25mm, it is recommended that if the question is correct, draw two parallel lines with a distance of 25mm.

Third: Draw separately.

That is, first draw two parallel lines with a distance of 2cm; Draw two more parallel lines with a distance of 5mm.

That is, "two pairs of parallel lines".

Hello, although it is simple, this is also a geometry problem. In the fourth grade of primary school, I only learned some very simple geometric knowledge, such as straight lines, line segments, squares, rectangles and other basic knowledge. Therefore, the fourth grade of elementary school cannot be a high-level, incomprehensible question.

Parallel lines are infinitely extended to both ends with no intersections. From this, it can be seen that the two lines are straight lines.

The distance in the question is two centimeters, five millimeters.

So, just draw two parallel lines with a distance of 25 mm.

According to the understanding of children who are in the fourth grade of elementary school. That's the answer.

a.The distance between the two lines is 2cm, and the length of the line is 5mm

Start with a ruler (raid.

Triangle) draws a 5mm line, the ruler stays still, then use another triangle (the right angle) next to the ruler, then the ruler rises 2cm next to the triangle (the right angle), and finally draw another 5mm line. (It is better to mark the distance of 2cm and the length of 5mm).

b.If you want to say that it is a parallel line, it must be two, so draw two kinds according to the above method 1Distance 2cm 2The distance is 5mm (parallel lines are straight lines).

c.I can't help it, go find your teacher.

Parallel lines are straight lines, which are infinitely long, and there is no length or shortness, and the title should be changed to parallel line segments.

a Draw 2 straight lines parallel to each other.

Methods of communication (Method 1: With the help of the third line of the method version.

2. Use parallel weight tick marks).

Method Comparison: Which Method Do You Prefer? Why?

b Draw 2 parallel lines at a distance of 2 cm and parallel lines at a distance of 7 cm.

Methods of communication, see ** demo.

Get: The choice of which method to draw parallel lines is determined by the distance between the two parallel lines.

Method 1 is suitable for drawing two parallel lines where the distance between them exceeds the parallel tick marks on the ruler.

Method 2 is suitable for drawing two parallel lines that do not exceed the parallel tick marks on the ruler.

Summary: Use the appropriate drawing method flexibly according to the specific situation.

I don't think it's the cause of a typographical error. The inscription should be to draw two parallel lines with a distance of 2 cm and a length of 5 cm. That's what I've said, otherwise even adults can't read it, and how can a fourth-grade student read it?

Nowadays, pirated books are rampant, and teachers seem to be in charge of it, and everyone knows what this means!

A bunch of pigs who published the book cobbled together and wrote nonsense with only one purpose, money, my child in elementary school, and encountered too many such questions.

Alas, the children of men.

Draw two sets of parallel lines, with a distance of 2cm and 5mm between each set of parallel lines

Draw two parallel line segments with a distance of 2 cm and 5 mm.

The distance between the two parallel lines is 2cm

Wire length 5mm

In fact, it is to draw two parallel lines with a distance of 2 cm and a parallel line with a distance of 5 cm!! Two separate)

That is, the distance between the two parallel lines is 2 cm, and the two parallel line segments are 5 mm long

Draw a 5mm line first, then use the ruler to pan down 2cm, and then draw a 5mm long line.

**What's the title?

Is it possible that the distance between parallel lines is 2 cm and the width of the line is 5 mm?

It's a boring topic, what are you entangled in! Waste of energy!

The distance between the two parallel lines is 2cm, and each parallel line is 5mm long

Parallel line segments with a distance of 2 cm and a length of 5 mm ......Actually, this is a language question, haha. However, 5mm is a little shorter......

This is an expression error, and most of the current books have not been corrected, and they are all for the sake of money and no quality.

It should be drawn in two groups, one group is 2 cm apart. One set is at a distance of 5 mm. That's all I can understand.

Draw two parallel lines with a 5mm segment and a distance of 2cm between the segments

I think it's a parallel line with a distance of 2 cm and 5 mm.

==I should draw two lines parallel to each other, and the two lines should be 2 centimeters or 5 millimeters apart.

What is the punctuation mark in the middle of 2 cm 5 mm?

Is this a math problem or a brain teaser...

A stupid way, with a pencil (erasable off), you first draw a rectangle, the long side is 2 cm, the short side is 5 mm, and the long side (2cm side) is erased after the drawing! cm is centimeter, mm is millimeter.

The distance between the parallel lines is 2cm, and each parallel line is 5mm long

5 pens + 4 brushes = 50

4 pens + 5 brushes = 45

Subtract 1 pen - 1 brush = 5

A fountain pen is 5 yuan more expensive than a brush.

Fountain pen x brush y

4x+5y=45

5x+4y=50

The second formula minus the first formula.

x-y=5, that is, the fountain pen is 5 yuan more expensive than the brush.

Let the fountain pen ** be x and the brush ** be y

4x+5y=45, 5x+4y=50, subtract the two formulas to get x-y=5, that is, a fountain pen is more expensive than a brush 5 yuan.

1. Solution: It takes 360 60 = 6 (hours) for trucks to go from A to B, and 360 40 = 9 (hours) for passenger cars, but the trucks arrive at B and stay for hours, and the buses have gone for a total of 6 + 05 = hours, a total of kilometers have been walked, and the remaining 360-260 = 100 kilometers have taken two cars for a total of 100 (60 + 40) = 1 hour, so it takes hours from departure to meeting).

2. The method is the same as above, the answer is 15 minutes, and you can understand it by yourself.

1: 360 60 = 6 hours 6 40 + 40 km (360-260) (60 + 40) + 6+ hours.

Answer: Hours meet.

Two: 1200 100 = 12 minutes (1200-12 60) 100 = minutes minutes.

A: Total minutes.

1. Set up the truck to return to meet in x hours.

40×（x+360÷60+

40x+260+60x=360

x=11+360 60+ hours).

2. Let's meet after x minutes.

100x+60x=2400

x = 15 after 15 minutes of encounter.

43-11) 2=32 2=16 (years).

16-11 = 5 (years).

A: After 5 years, it is 3 times.