Hurry up and help me think about it, trouble 20

Let the distance between abs be s, then.

According to the title: 800 V A = (S-800) V B has: (800 + S-400) (S-800 + 400) = (S-800) S

Thus the value of s is introduced, and it is found that there are two values, and the distance is a positive number, so take a positive value!

Let the distance between abs be s, then.

According to the question: 800 V A = (S-800) V B.

Then there are: (800+s-400) (s-800+400)=(s-800) s

Haha, it's so simple. Think of it this way: meeting once means walking the whole journey together. I walked the whole course three times. So.

The distance between A and B is 1400 meters.

There is a keyword "constant velocity" in this question, I don't know if it means that the speed of A and B is the same?? If it's the same! The answer is 1600 meters!!

800 V A = (x-800) V B.

800+x-400) v B = (x-800 + 400) v A.

Explain. 800+x-400）/（x-800+400）=（x-800）/ x

x=……You know how to set it up.

x=2000

Sample, I don't give you homework, you get here and let someone else do it for you? It's okay, you! I'll go to school and punish you, boy!

Your math teacher.

Why do you keep doing math problems?

You're definitely a tabula rasa! All the questions you don't know are posted online!

Uncle won't tell you.

On the 2nd floor, I'll make you laugh at me.

The landlord is too.,If you don't understand, you sent it to this place.。

I'm ftwo.

The conversation on the second floor is very humorous.

Hehe, mathematics should be serious, simple, think for yourself, find your own ideas.

Ask your classmates.

I graduated from junior high school. If you ask me a few words about China, I still understand it. I don't know if there is a mistake in Chinese English among me.

Dizzy. I also put the junior high school questions to answer.

1.Strict and responsible, is a very serious teacher. I put a lot of thought into teaching and gave me a lot of guidance.

In addition to studying, the teachers also taught me a lot of life lessons. I hope that the teacher can be more active in teaching in the future 2 I have set myself the goal of ......I'm going to move towards that goal. In terms of study, I will work harder.

After class, I also want to enrich my life and learn some strengths, such as practicing calligraphy, writing, and guitar [combined with my own situation] 3, English, my strength is ......The weakness is ......【Listening, Reading, Writing, Choice】I want to strengthen ......Training is not relaxed ...... either. History, I will look for some relevant reading materials, hoping to strengthen my understanding in addition to letting my hands die. Do it to improve .........

It was my high school idea, and I knew it would work.

x>=1

x<3 so is 1 = integer solution is 1 and 2