Please help me solve the following problems, please help me solve the following problems, I will con

1. Set the speed of Xiaozhang's bicycle to be A, and the tram to be B, and send a car every X minutes.

When Zhang meets a bus, the distance between the car behind them is B by X. When a car behind caught up with Zhang, Zhang drove off:

A takes 12 minutes, and the next car travels: B x + A x 12 = B by 12Namely:

b*x+a*12=b*12

When Zhang meets the bus in front of him, the next car he meets will meet with them at this time: B by X. At this time, it is equivalent to the metre between the tram and Xiao Zhang in 4 minutes from B x kilometers. So: b*x=(a+b)*4

It can be found from two formulas: x = 6 minutes.

2. I was called out by my wife to look at household appliances halfway through the writing, and I won't copy the next one yet.

3. The whole journey takes time: 10000 210 + 5 = It seems that the question is a bit problematic, and there should be no decimals. ）

Decelerate after X minutes.

The walking distance before deceleration is: 104*x

The stroke after deceleration is: 84*(

104*x+84*(Find x.)

2.The simplest way to think about it is to calculate the speed of A and B. Find out how long it takes. Just subtract it. So. Set the speed of the car xB car speed y

Departing from both places. Meet after 4 hours - >4x+4y=total distance. This equation *3

Walk for another 3 hours. 10 km and 80 km from each place - >3x+3y+90=total distance. This equation *4

Then the 2 equations are subtracted. Total distance = 360

Car A traveled for 4+3 hours. It is still 10 km from place B. So.

7x = 4+3 hours after car B has been traveling. It is still 80 km from place A. So.

7y = so. A car still takes 1 5 hours. That is, you can get to place B in 20 minutes.

And car B still needs 2 hours to get to place A. So. Derived.

After car A arrived at place B. Car B will take another 1 hour and 40 minutes to get to place A.

The first floor goes up to the fifth floor.

5-1 = 4 floors.

So it takes 4 5 4 = 1 5 minutes to go up to the 1st floor.

1 to 4 floors up 4-1 = 3 floors.

So 1 5 3 = 3 5 minutes.

Remember to Oh Answer:

1) The chemical formula of Cu2(OH)2CO3 = 2CuO+H2O+CO2 2)D is: CO2

If E is a elemental substance or an acid and D is the same substance, then the chemical formula of D is: H2O If E is a elemental substance or an acid and F is the same substance, then the chemical formula of F is: Cu3) Cu+2AGno3 = 2AG+Cu(NO3)24) Answer: CD

(1) A bag of flour, the first time I ate 40% is 5kg more, the second time I ate 80% of the first time, at this time there is still 12kg of flour left, how much is this bag of flour?

The second time I ate 40% 80% = 32% and 5 more 80% = 4 kg.

Flour originally was: (4+5+12) (1-40%-32%) = 75 kg.

2) Workers transport 250 porcelain, stipulate that the complete transport of a destination to the destination to pay 20 yuan, damage a compensation of 100 yuan, after the shipment of this batch of porcelain, workers have 4400 yuan, how many porcelain they damaged in total?

Suppose they damaged a total of x porcelain.

250-x）×20-100x=4400

Solution x=5A: They damaged a total of 5 porcelain.

3) A project, A alone does 18 days to complete, B alone to do 15 days to complete, and now it is decided to be completed by A and B together, but A has something to do in the middle of the leave for 4 days, so how many days A actually did when completing the task?

Set to complete the task when A actually did it for x days.

1/18 x+1/15 （x+4)=1

Solution: x = 6 Answer: A actually did it for 6 days when he completed the task.

4) A cat and a mouse move in opposite directions in the same place in a circumference with a diameter of 100 meters, the cat runs meters per minute, and the rats run meters per minute. When the cat and the mouse meet again, how many meters does the cat walk more than the mouse?

100 minutes.

Cats walk more than rats: (m.

Warm – cool Hot – bitterly cold Inside – Outside Hot – Cold.

Illustrative method: Interpret.

Warm, cool. Inside, outside. Hot and cool. Winter, summer.

Ahh I'll help you sprinkle.

1.The density is calculated as: p=m v

2.Nature is the most dense. It seems that the class thinks that it should be diamond, because it is the hardest material in nature, so it is also very dense.

3.This is because, when you are shaking the water bottle quickly, the atmospheric pressure inside the bottle is less than the atmospheric pressure outside the bottle because of the fast flow rate, so it is not easy to leak out.

It's a principle in junior high school physics, and you can try it, Hehe.

4.Math, I'm probably not very good at it.

5.(1) You should be stationary with the bench, and 2) you should know how to maintain a balanced distribution of the gravity you are subjected to.

Children are not allowed to go to school, Hehe).

6.This uses the principle of leverage, and we first need to know that l1f1=l2f2

Then, find out where the power arm is most effortless, the outward-facing the better, but don't overdo it (hey, not too detailed).

7.For example, lubricating oil will be added to our self-envy hole driving, which is to reduce friction, so it is also labor-saving.

8.Because of the new money, the hardness is OK, and the front edge is very thin, because the hardness is OK. According to the physical principle that the smaller the force area, the greater the pressure.

So he can cut through the paper, but fast.

9.The balance should tilt to the right. Because the quality of water in the beaker is the same, put it on the right side like a weight.

Although the weight will exclude drinking water of the same mass as him, which is part of the chapter of the law of buoyancy, but. The discharged water will be caught by the tray, so the right side is heavy and the balance is tilted to the right.

My Li is gone, you can use it if you want it. Hee-hee. m

p=m divided by the mass of the object with v density divided by the volume. Nucleus...

There are too many questions, and I have to write it myself, Wang Renqiao, and find some answers on the Internet.

..2. Metal, ice, there are too many problems