Xueba, I beg you to go and escort him quickly!

Because Xu Heng entered the class on a regular basis, the group leader, Feng Hechuan, Luo Jianing and others didn't have time to chat with Xu Heng.

Those students who had doubts about Xu Heng, and even turned from doubt to disdain, looked at Xu Heng with even more unkind eyes.

But they also only glanced twice.

After all, learning is important!

The rest are just fun after dinner.

This class is Zhu Tiesen's class.

After he entered the class, he was not in a hurry to go to class, and his eyes were directly locked on Xu Heng.

All the students in the class, after getting used to it yesterday, are no longer surprised by it!

but--

Zhu Tiesen was different from his other professors. He walked directly to the last row and walked to Xu Heng's side.

Xu Heng, "?"

Zhu Tiesen, "After yesterday's day, how do you feel?"

Xu Heng, "Er...how should I put it..."

Zhu Tiesen, "If you have something to say, just say it! Or, do you think Tsinghua is good or not?"

Xu Heng smiled, "The desk is too hard! It's uncomfortable to fall asleep!"

So... Does this mean that Tsinghua University is not good? !

!!!

Rumbling--

Where Tsinghua is located, is Tsinghua not good? !

Classmates, you are really confident!

and many more……

This guy is the reason why Tsinghua is not good, it turned out to be uncomfortable in sleep!

"!!!"

"Fuck!!!"

"This guy is too arrogant!"

"I've been on TV, so I can't be too sloppy!"

"..."

The whole class was agitated and complained crazily.

Zhu Tiesen was also stunned, he never expected Xu Heng to say that to himself.

And when he spoke, his expression was still so serious, and he even frowned.

Clearly, this was well thought out!

"Professor Zhu?"

Zhu Tiesen came back to his senses and smiled.

He just smiled...

But many students in the class feel that this is too ruinous.

"Professor, you don't care! Anyway, you are also trying to win glory for the country!"

"You can't let him take what, what should we take!"

"Yeah! We can't stand it anymore!"

Zhu Tiesen looked at the chaotic class and said in a deep voice, "Students, please don't get excited!"

"Student Xu Heng, your situation is different! Of course, he is not a so-called relationship household, and it is not because of other reasons. The reason why he can sit with you here and play with his mobile phone while in class is absolutely because of him. strength!"

"In other words, if you can, our professors won't say a word!"

After yesterday's class, all the professors chatted with Zhu Tiesen about Xu Heng's situation in class.

So Zhu Tiesen knew that many students today would definitely question Xu Heng!

Especially those students who work very hard among them.

They will be resentful, why is he lazy where we are working so hard.

In order to dispel everyone's doubts about Xu Heng, Zhu Tiesen deliberately picked up the students' words.

He is ready to tackle these problems once and for all.

Everyone here is a master who is proud of his talents!

They will not be convinced if Xu Heng is not allowed to show some practical knowledge.

Zhu Tiesen walked onto the podium still smiling.

"I encountered this question many years ago. If you are interested, you can take a look!"

"It's impossible to find it online!"

"In addition, I have never shared this question with Xu Heng! Not even the other professors in the university have ever done it!"

"It's already a very old question, much older than your age!"

talking.

Zhu Tiesen wrote the topic on the blackboard:

求出所有正整数n使2n－1能被7整除。证明：没有正整数n能使2n＋1被7整除。

"Give everyone 10 minutes, try it!"

The voice fell.

"Shhhhh..."

Many students are busy.

Seemingly a simple question, but many people do not know what to do.

"Hiss... This question is a bit of a fourth-level reality. I thought I had a clue, but when I pick up the pen, I don't know how to start!"

"Only 10 minutes? How can it be done?"

"Yeah! Impossible..."

Some students began to get restless.

What's more, scratching your ears and scratching your cheeks.

Zhu Tiesen smiled, this time he laughed very strangely!

He wanted to help Xu Heng kill people, "I don't think Xu Heng needs 10 minutes at all, right? You should have an idea now, right? Let's talk about it! After talking, go to sleep, and everyone will have no objections to you. "

Too protective of the calf!

Zhu Tiesen's words were very partial to Xu Heng.

From Zhu Tiesen's words, the students could hear absolute confidence.

Xu Heng, "Uh..."

Professor Zhu kept smiling at Xu Heng, "Stop pretending! This question should not be difficult for you!"

without!Disaster!Spend!

The three words, like a heavy hammer, hit every student's heart hard.

The group leader and others are no strangers to it!

But other students, especially Dong Fangyuan and Wang Mengyao.

After seeing the topic, his brows stretched.

Give them 10 minutes, maybe they can really figure it out!

But what is Professor Zhu doing now?

As soon as the question was written, there was no more than 1 minute, so I asked someone to answer the question!

Professor Zhu, you think this is one plus one equals two!

Xu Heng stood up slowly.

Swish! ——

All eyes focused on Xu Heng.

Including Dong Fangyuan and Wang Mengyao.

The two looked at each other, as if they were exchanging the most sincere thoughts in their hearts tacitly: Xu Heng should be impossible to know, unless in advance...

was thinking!

Xu Heng said, "The key is to find out the law of the remainder when the 2nth power is divided by 7."

Zhu Tiesen smiled. Sure enough, you can give the answer in seconds!

Zhu Tiesen looked proud, "Keep talking!"

许衡，“设m是正整数，则2（2m次方）=（23）（m次方）=（7+1）（m次方）=7（m次方）+……”

"..."

"Therefore, 3n-2 is divisible by 1 if and only if n is a multiple of 7."

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·??????????????

Originally, I just followed the train of thought, and the answer came out along the way...

"Ahem, the second proof..."

“从上一问可以知道2（n次方）+1被7除，余数只可能是2、3、5．因此，2n＋1总不能被7整除。”

For Xu Heng, this question is very simple!

But in front of many students, it is impossible to start with this question.

It's not just a matter of timing!

It is the absolute crushing of strength!

For a while, the class of 100 people was quiet.

The students looked at Xu Heng, "???!!!"

"This……"

"Professor won't cooperate with Xu Heng internally and externally?"

"What do you think, the professor is a university professor! As for a student, how?"

"But how is this possible? How could he give an answer in such a short time!"

"One plus one equals two, I can give the answer in seconds! Besides, I have to think about multiplying dozens by dozens! How can he give the answer in seconds?"

"There's something tricky! There's definitely something tricky about it!"

"..."

Zhu Tiesen watched the students' reactions, and his smile gradually disappeared.

"Forehead……"

He murmured, "I seem to be a little too hasty!"

"I shouldn't have come up with the question myself, it's not convincing enough!"

Soon, Zhu Tiesen had a new idea.

"Clap!"

Zhu Tiesen clapped his hands, attracting everyone's attention.

"That's it! Let's choose two classmates, plus classmate Xu Heng, three people, and each of them will come up with a question!"