Olympiad math questions, please teach netizens, pay attention to the equations, thank you!!

The statement that happened Feng Shaofeng Fei is all in the way.

Set the x of the whole journey when sleeping

then x*1 3+x=1-1 3

x=1/2

Analysis: If the distance traveled by the train during sleep is taken as the unit 1, then there is still 1 3 left, and the distance traveled by the train before sleeping is 1+1 3=4 3.

As can be seen from the title, when you start sleeping, the ratio of the untraveled distance of the train to the whole journey is: 1-1 3=2 3, so the whole journey is: 4 3 (2 3)=2

So the distance traveled by the train during sleep accounted for 1 2 of the whole journey. Columns into a general formula:

A: When I slept, the train traveled half the distance.

（1-1/3）÷（1+1/3）

The distance traveled by the train while sleeping accounts for 1 2 of the whole journey.

Suppose the distance traveled by the train while he sleeps is x, and the total length is 1, then the distance after waking up is x 3, and the equation is played.

1/3+x+x/3=1

The solution is x=1 2

So the distance traveled by the train while he slept accounted for 1 2 of the whole journey

According to the inscription: 4 3 times the distance traveled by the train while sleeping is 2 3 times the whole journey

Therefore, the distance traveled by the train while sleeping is the whole journey: (2 3) (4 3) = 1 2

When I started sleeping, there were still 2 3

So, let's sleep x of the total distance

x+1/3x=2/3

Get x as 1 2

Let's assume that the train distance is x when he sleeps and x 3 when he wakes up

1/3+x+x/3=1

The solution is x=1 2

So the distance traveled by the train while he slept accounted for 1 2 of the whole journey

Let the whole journey be s, and the distance traveled when sleeping is x, s=1 3s+x+1 3x, and the solution is x=1 2s, that is, the distance traveled while sleeping accounts for 1 2

I saw it in my winter vacation homework, and I told you.

It's a third.

The 2nd floor is recommended for you to see.

I get it (I'm also a question checker) (Thank you.)

Have you ever studied equations?

Featuring x number of fighters.

30x+360=(30+5)(x-8)

The solution is x=128

128 times 30 plus 360 equals 4200

128 fighters 4200 pounds of cargo.

First of all, the three kinds of grains are: 10, 15, 25 kg, ** the highest preparation is from high to low, from more to less, so, toffee 25, chocolate 15, fruit 10, the lowest preparation: halva 25, fruit: 15, chocolate 10

2:3=4:6

The ratio of the number of stamps collected by Xiaohong, Xiaogang and Xiaohua is 4:6:134+6+13=23

Little red 230*4 23=40 pieces.

Xiaogang 230 * 6 23 = 60 pieces.

Xiaohua 230 * 13 23 = 130 pieces.

If you look at the ratio as the number of stamps they have, that's 4 to 6 to 13, which adds up to 23 and ends up with 230 times it.

The number of stamps of Xiaohong is 2 3 of Xiaogang, and the number of stamps of Xiaohua is 13 6 of Xiaogang. Therefore, the number of stamps of Xiaogang can be calculated as: 230 (1+2 3+13 6)=60, and then Xiaohua: 130, Xiaohong: 40

Xiaohong: Xiaogang: Xiaohua = 4:6:13

The number of stamps collected by Little Red is 4x

23x=230

x = 10 The number of stamps collected by Little Red is 40

Xiao Gang collected 60 stamps

The number of stamps collected by Xiaohua is 130

It's a simple question for the fourth grade of elementary school.

Assuming that Xiaogang collected 6x stamps, it can be seen according to the proportional relationship: Xiaohong collected 4x stamps, and Xiaohua collected 13x stamps.

The column equation is: 4x+6x+13x=230

The solution is x=10

The number of stamps for the three persons is 40, 60 and 130 respectively.

I wonder if you've ever learned to set an unknown x?

If the number of stamps collected by Siu Gang is 6x, the number of votes for Siu Hung is 4x and the number of stamps for Siu Wah is 13x. Then:

6x+4x+13x=230

Available: x=10

Then: 6x=60

4x=4013x=130

A: 60 stamps for Xiaogang, 130 for Xiaohua and 40 for Xiaohong.

Since the ratio of the number of girls to the number of boys is 5:8, the number of girls = 5 13 * the total number.

So it seems that the total must be a multiple of 13, so that between 45-55 only 52 matches, which is 52 students.

The ratio of boys to girls is 8:5, so the total number of students is 13, so the class size is a multiple of 13 (the whole is not half of the total).

So between 45 and 55, only 52 is a multiple of 13, so there are 52 in the class, so there are 32 boys and 20 girls.

The ratio of the number of girls to the number of boys is 5:8, so the number of girls and the number of boys are 5k, and 8k (k is a positive integer).

Then 45<=5k+8k<=55

That is, 45<=13k<=55, so k=4 (verified to know), so the number of girls and boys is 20 and 32, respectively

5+8=13

The multiplier of 45 between 55 and 13 is only 52

Solution: The number of children:

28+24) (5-3) = 26 people.

The number of pears: 3*26+28=106.