Hehe, I haven t seen the elementary school math problems that you must not be able to answer

There is a serious logical contradiction in the setting of this topic.

One of the conditions is that the dog runs between people, that is, the dog does not overtake people.

The other condition is that at 0s the three of them move together.

And the speed of the dog is greater than theirs.

That is, at an infinitesimal point in time.

Dogs are bound to outnumber people.

No matter how small the time.

Running backwards, they were five hundred meters apart, still at that speed, the dog ran back and forth between them, and finally they were at one point, and that point was the original point.

2+3)*x=500

x = 100 (seconds), where A is 200m away from the origin

Because the dog is a non-stop runner.

So a total of 10*100=1000 meters were run.

Location:.. Ah, I can't do it.

When A and B are 500 meters apart, it takes 500 (2+3) = 100 seconds, which shows that they took 100 seconds.

The conditions of the question are insufficient.

How much did A walk before the dog started chasing? ）

Answer: First calculate how many trips the dog has made between A and B, and then calculate its footing.

300 meters away from A and 200 meters away from B.

I guess so.

The asymptote is x(+,2y=0

y=（+，1/2）x

So b a=1 2

So a=2b

The hyperbolic equation can be set as.

x 2 4b 2-y 2 b 2 = 1 (a>0, b>0) and x-y-3 = 0.

3y 2-6y+4b 2-9=0

Let the intersection points of the hyperbola and the straight line be (x1,y1),(x2,y2), then the two roots of the above equation are y1 and y2

Then y1+y2=2,y1*y2=(4b 2-9) 3x1-x2=(y1+3)-(y2+3)=y1-y2 and the quadrature of the chord length obtained by the hyperbolic truncated line.

x1-x2)^2+(y1-y2)^2

2(y1-y2)^2

2(y1^2+y2^2-2y1y2)

2[(y1+y2)^2-4y1y2]

2[4-4(4b^2-9)/3]

8[1-(4b 2-9) 3]=(8 3 3) 2=64 3, so 1-(4b 2-9) 3=8 3

3-(4b^2-9)=8

b 2 = 1 solution to b = 1 (because b > 0).

So the hyperbolic equation is x 2 4-y 2 = 1 (a>0, b>0).

The two asymptotic lines are x+-2y=0

Let the hyperbolic equation be .

x 2-4y 2=m and x-y-3=0 syntactic elimination y3x 2-24x+m+36=0

Set the end points of the string a(x1,y1), b(x2,y2)x1+x2=8, x1x2=12+m 3

ab|=√2√[(x1+x2)^2-4x1x2]=8√3/3√2√[64-4(12+m/3)]=8√3/3==> m=4

The hyperbolic equation is x 2-4 y 2 = 4

i.e. x 2 4-y 2 = 1

You don't have to worry about what type of hyperbola it is, just write the asymptotic equation to find the bibo.

Curve equations, naturally find out the conditions that are met.

hyperbolic equations.

If you know that the asymptote is px qy=0

The hyperbolic equation is p 2x 2-q 2y 2 = m(m≠0).

There are 3 people on the left side of Xiaohong (it is counted after distinguishing the left and right of Xiaohong), and the number of people on the right is given by the title, don't look at the picture, so there are 7 people in total.

There are (2) people on Xiaohong's left and 3 people on the right, and there are (2+3+1=6) people in total because she includes herself

Hope it helps.

The goal is wrong.

If there are three people on the right, there should be two people on the left, and six people on the left.

There are 3 people on the left, three people on the right, and 7 people on their own. The person who made the question is funny.

There are 4 people on the left side of Little Red, and there are 6 people in total.

There are (3) people on the left and 3 people on the right, for a total of (7) people.

The right side of the title should not be drawn, so don't dwell on it.

There are 3 people on the left and 2 people on the right, for a total of 6 people. It may be that there is a mistake in the volume, and it is better to believe in a book than to have no book!

1.（10）+5=13+2

In this question, just make the left and right equal.

In the end, the children's shoe store left 21 yuan for his own money, 15 yuan for shoes, and 50 yuan for neighbors, so the money lost was 50 + 15-21 = 44 yuan.

The expenditure is: 29 (for the young man) + 15 (for the cost) + 50 (for the neighborhood) = 94

Income is: 50 (borrowed).

The loss is: 94-50=44

The money paid by the children's shoe store is 15 + 29 + 50 = 94

Really got the money: 21

Loss: 94-21=73

When the shoe store went to change money first, he got 50 yuan, and then found 29 yuan for the young man, and also lost 29 yuan, and the cost was 15 yuan, and the first time a total loss of 29 + 15 = 44 yuan. After discovering that it was counterfeit money, the shoe store lost another 50 yuan. So I lost 44 + 50 = 94 yuan, but I got 50 yuan when I exchanged money, and I lost a total of 94-50 = 44 yuan.

The cost of shoes is 15 plus the money for the customer is 29

As for changing change and then returning it, it doesn't matter. But if you don't pay back the neighbor, the shopkeeper still makes 6 fast, and the neighbor loses 50

It can be simplified to that the cost of the shopkeeper's shoes is 15 yuan, and the selling price is 21 yuan, and a customer buys shoes with a fake money of 50 yuan, and the shopkeeper finds him 29 yuan.

How much does the shopkeeper lose?

In short, it has nothing to do with the neighborhood, the children's shoe store lost in this transaction is the young man's earning, the young man got 29 yuan and a pair of shoes, from a mathematical point of view, the children's shoe store lost 29 + 15 = 44 yuan in this transaction, from an economic point of view, the children's shoe store lost 29 + 21 = 50 yuan in this transaction.

There are two answers: one is the cost loss: 44 yuan and the other is the profit loss: 50 yuan.

Detailed analysis of 44 yuan: before buying shoes, the shoe store owner 0 yuan, got 50 yuan in counterfeit money for the neighbor's real 50 yuan, the boss earned 50 yuan (+50), gave 15 yuan (-15) to a pair of shoes that bought shoes, gave him 29 yuan (-29), was found by the neighbor, gave the neighbor 50 yuan (-50), that is, (+50) + (15) + (29) + (50) = -44 yuan.

Detailed analysis of 50 yuan: first of all, Xiaomi Butong shoes store took 50 yuan counterfeit money to the neighborhood for 50 yuan change, when the neighborhood knew that it was counterfeit money, Xiaomi Butong shoes store lost 50 yuan, so this process can be understood as: Xiaomi Butong shoes store took 50 yuan of real money to the neighborhood to exchange 50 yuan for change, this link Xiaomi Butong shoes store did not lose.

In addition, the transaction between the millet step children's shoes store and the young people is also the main link, the young people use 50 yuan counterfeit money (that is, they did not spend a penny) to get a pair of shoes with a cost of 15 yuan and 29 yuan in cash recovered from the millet step children's shoes store, which is the loss of the millet step children's shoes store, it should be 15 29 44 yuan, if this is the case, but is this really the case? No. Because, the Xiaomi Butong shoe store is traded with young people at 21 yuan, so if it is calculated at 15 yuan, the Mi Butong shoe store will lose 6 yuan of profit, therefore, the loss of the Xiaomi Butong shoe store in this transaction should be 15 29 6 50 yuan.

Children's shoe store income: 50 yuan.

Children's shoe store expenditure: 29 (looking for money) + 50 (losing money) + 15 (cost price of shoes) = 94 yuan.

Loss = Expenditure - Income = 94-50 = 44 yuan.

The children's shoe store lost 44 yuan.

Obviously, the loss of the shoe store is a pair of shoes, 29 yuan found, 50 yuan to compensate the neighborhood, a pair of shoes should be calculated based on the market value, that is, 21 yuan, just like a store has a fire, the statistical losses are the market value, the 29 yuan found and the compensation of 50 yuan are the owner's own pocket, so the loss is 50 + 29 + 21 = 100 yuan.

If it's an elementary school math problem, that's it.

It's different if it's a reality, you have to pay tax on every transaction you make, and the tax office won't tax you because you're trading at a loss.

In addition, cash also has a time value, and the 29+50 yuan you lose is cash, and you lose its time value! What does it mean for a small business like a shoe store, in particular? Anyone who has done business knows that you lost the 79 yuan, how to make up for the capital chain?

You have to borrow, and you have to pay interest on the borrowed money, and here the interest can also be understood as the value of the time you pay to others!

Therefore, the loss of the shoe store should be greater than 100 yuan.

To put it simply, he received a counterfeit 50 yuan bill, because it was the same as the neighbors.

Young people use 50 = 21 shoes + 29 money.

Shoe store loses $29 in cash (for young people) Shoe money (15) = $44.

Lost $73 to a neighbor $50 and $29 to a young man.

Shoes went out and got 21 yuan and earned 6 yuan.

Let's assume that the money is real, and the shoe store owner made 21-15=6 yuan after the transaction, and it turned out that the 50 yuan was fake money, so another 50 yuan went out from the shoe store owner, and the shoe store owner lost 50-6=44 yuan.

The trapezoidal upper bottom length (17 + 10) 4-1) = 9 (cm) and the lower bottom length is 9 4 = 36 (cm).

Originally, the square had a side length of 19 + 10 = 19 (cm), so the height of the trapezoid was 19 cm.

The area of the trapezoid is (9 + 36 ) 19 2 = (square centimeters).

Difference 17 + 10 = 27

Bottom: 27 (4-1)=9

Top bottom: 9*4=36

High: 9+10=19

Area = (36 + 9) 19 2 = square centimeters).

Let the side length of the square be x

Then the upper bottom of the trapezoid is x-10, and the lower bottom is x+17

Since the bottom bottom is 4 times that of the top bottom. x+17=4(x-10) calculates x=19

The trapezoidal area is (x+17+x-10)*x 2, and bringing x in is the answer.

Let the sides of the square be x centimeters.

x + 17 = 4(x-10)

The x=19 trapezoid has an upper base of 19-10=9, a lower base of 19+17=36, and a height of 19 on the sides of the square

So the area of the trapezoid is (9+36)*19 2=square centimeters.

Let the original side length of the square be x

then there is x+17=4*(x-10).

Get x=19

Therefore, the upper bottom of the trapezoid is 19-10=9, the lower bottom is 19+17=36, the height is 9, the area of the trapezoid=(9+36) 2 *9= square centimeters.

The additional 400 square centimeters is the area of the sides of the two sectors, each is 200 square centimeters, and the height is 20 centimeters, so the radius of the bottom circle is 10 centimeters, so the volume is 10*10**20=2000 cubic centimeters.

400 square centimeters is the product of the radius of the bottom of two cylinders multiplied by the height, 400 2=200 is the product of the radius of the bottom surface of the cylinder multiplied by the height, 200 20=10 Knowing that the height of the cylinder is 20, the radius is 10, so find the volume of the cylinder.

After spelling, there are two more sides with a long radius:

The surface area of the cuboid is two sides more than the cylindrical surface area. The area of the two sides is 400 square centimeters. The height of the cylinder is 20 cm, so the radius of the cylinder is 400 2 20 10 cm (the side area is the height of the cylinder multiplied by the radius of the cylinder).

With height and radius, the volume of the cylinder is 10 10 3 14 20 6280 Is this a line?