If there is a wood, there are people, and if there are any, send a math problem!

1.The home is S kilometers away from the school, and the time it takes for the sisters to meet is T by the title, and the sum of the walking distance of the Xiaohong sisters is 2s

Xiaohong walked a kilometer for her sister, enough for an S, Xiaohong walked an S by herself) Both of them have been walking and walking, and it takes the same amount of time, because of the difference in speed, which leads to the difference in the distance traveled (that is, 2 kilometers, back and forth).

1 12 - 1 20) t = rollout t= 24 minutes.

Find t and use s = + t (1 20) or s = t (1 12).

s = km. 6/7-3x=3/14

3x=6/7-3/14=12/14-3/14=9/14x=3/14

1.Set Xiaohong's home away from the school to x

Then the time for the sister to go is: x (1 12) +

The distance traveled by the younger sister is:

So: (1 20)*(12x+.)

x= 6/7 -3x=3/14

3x=9/14

x=3/14

1.Set the time to go is t

1/12 t - 1/20 t = * 21/30 t =

t = 24

So the distance s=24*1 12 - = km2 6/7-3x=3/14

3x=6/7-3/14

3x=9/14

x=3/14

1. Set up Y meters away from the school, and walk for x minutes when we meet.

y=1/12*

y=1/20*x+

x=24y=

2、x=3/14

1: Solution: Set Xiaohong's house to be x kilometers away from the school, according to the question.

x+ solution gives x=

A: Xiaohong's home is kilometers away from the school.

2: Solution x=3 14

1) Known v1=1000 12 v2=50 2 people are equal in time.

Set the distance between the school x ( x+400) 250 3 )=x-400) 50 50x+20000=(250x-100000) 3

75x+60000=250x-100000 175x=160000 x=6400/7 =

Meters from the school.

2) 6 7 -3x = 3 14 i.e. 3x=12 14 + 3 14 3x = 15 14

Get x=5 14

There are a total of x number of employees.

Because 27000 is greater than 25000, the number of people must be greater than 25 people Because of condition 2, the reduced travel fee is 20*(x-25), then the per capita cost is 1000-20*(x-25).

Therefore, we can get *x=27000 (multiplied by the number of people per person is the total number of payments) and solve the equation to get x1=45 , x2=30

Because it must not be less than 700 yuan and when x = 45, the per capita cost = 1000-20 * (45-25) = 600 is less than 700

And x = 30, per capita cost = 1000-20 * (30-25) = 900 is greater than 700

So a total of 30 employees went to Tianshuiwan Scenic Area for tourism.

Let the number of people be x

x*(1000-20(x-25))=270001000x-20xx+500x=2700020xx-1500x+27000=0

That's pretty much it, so let's figure it out for yourself.

According to the title, A and B need a total of 2*2 hours to complete this task alone, let A be x hours, then B is (4-x) hours, and the equation is listed.

1 (3x)+2 (3*(4-x))=11 6 The solution gives x=5 2 then 4-x=3 2

A needs hours, B needs hours.

The binary equation is:

Let it take x hours for A to complete and y hours for B to complete, and the equation is:

x/2+y/2=2

x/3+2y/3=11/6

The solution yields x= y=

Arithmetic Methods:

2 2 = 4 hours, A completes a task alone and B completes this task alone, a total of 4 hours, 1 hour, 50 minutes = 11 6 hours.

11 6 3 = 11 2 hours A completes a task alone and B completes (1-1 3) alone 3=2 tasks in total 11 2 hours.

11 2-4=3 2 hours This is the time required for B to do this task alone (2-3 2 1 2) 1 2 = 5 2 hours This is the time for A to complete aloneAnswer: It takes 5 2 hours for A to do it alone, and it takes 3 2 hours for B to do it alone.

1. All columns are one equation 100+ (x-100)*

The solution is x=8100 and the tree is 8100

100+ (8100-100)* in one class

So there are 8100 900 = 9 classes.

1.The home is S kilometers away from the school, and the time it takes for the sisters to meet is T by the title, and the sum of the walking distance of the Xiaohong sisters is 2s

Xiaohong walked a kilometer for her sister, enough for an S, Xiaohong walked an S by herself) Both of them have been walking and walking, and it takes the same amount of time, because of the difference in speed, which leads to the difference in the distance traveled (that is, 2 kilometers, back and forth).

1/20）×t

Rollout t = 24 minutes.

Find t and reuse s=

t×(1/20)

or s=t (1, 12).

s = km. 6/7-3x=3/14

3x=6/7-3/14=12/14-3/14=9/14x=3/14

The first row, the latter is -3 times the previous one, proportional to the series.

In the same column, each number in the second row is 2,-5+2=-3,7+2=9 from the first row

In the same column, each number in the third row is 1 3 times that of the first row.

It's all about the same (I'll answer the first question if I have something) (1) n*3 n (n=.)