The Sand Sculpture God is using magic to bully the boss again

"Is there no one else?" Luo Jiamao looked around, secretly feeling that there are so many children in the Xu family, "Have I closed the car door?"

"Wait." Yu Ziheng squeezed into the car behind Luo Jiamao, his schoolbag was bulging, and seemed to contain a large square box.

Xu Xing chased people away viciously: "What are you doing, are you going to fight?"

Yu Ziheng hugged Luo Jiamao and refused to leave: "No, the jigsaw puzzle he sent me yesterday didn't give me the finished picture or instructions. It's so scary. I dare not put it together. I'm staying at Luo Jiamao's house today, and Luo Jiamao also agreed."

Luo Jiamao couldn't break free from him, so he said to Xu Zhiyuan: "Uncle, can you go to my house first, put this person in and we'll leave."

Yu Ziheng was dumbfounded: "Aren't you going home to live?"

Luo Jiamao: "Don't worry, there is no one in our house."

Yu Ziheng: "..."

He began to play tricks: "I don't care, I will go wherever you go."

Xu Xingli: "Both of you get down for me."

Xu Zhiyuan asked: "Did Xingli send the puzzle yesterday?"

"Ah?" Yu Ziheng put the schoolbag on his chest, and took out the box of puzzles from it, "This one, Luo Jiamao sent it to me at noon yesterday, and the tone of his voice—"

Before he finished speaking, Luo Jiamao forcibly covered his mouth. It was an inexplicable dark history, so I couldn't explain it.

Xu Zhiyuan looked at the black, green and green jigsaw puzzle pieces, and naturally recognized whose handwriting it was, and asked Yu Ziheng: "Have you greeted your parents? If you don't mind, how many guest rooms are there in my house, one or two?"

"Two, it's best to arrange it next door, thank you uncle." Yu Ziheng was kind, "My parents know that I'm staying at a classmate's house today."

Xu Zhiyuan nodded: "Okay, when you arrive at the place in a while, you can send a location to your family, so that your parents can feel at ease."

Xu Xingli let out a long sigh: "Your behavior of picking up children at home is really dangerous."

Luring a wolf into a house has never had a good result!Why are her parents so holy?After driving these two people out of the car, she didn't think they would end up on the street.

Xu Zhiyuan pointed to the puzzle: "Isn't it a haunted house gift from you?"

Xu Xingli hummed a little tune and looked at the sky, as if he was indifferent to the world.

Yu Ziheng was shocked: "You gave this puzzle? Why did Luo Jiamao send it to my house?"

With a guilty conscience, Luo Jiamao said fiercely, "I just like to be a good person and do good deeds, can't I?"

Yu Ziheng: "..."

He silently put the puzzle back into his schoolbag, and decided not to bother with this fool.

Yu Ziheng caught a glimpse of a test question in his schoolbag, took out a crumpled piece of paper, and handed it to Xu Xingli and Yun Yan: "Look at the question our teacher left for us today."

Xu Xingli glanced at it, the question was interesting.

Let the positive integers a and b satisfy (a^2+b^2)/(ab+1)=k∈N, and prove that k is the square of a certain positive integer.

In math problems, generally speaking, the shorter the questions, the more difficult the questions are. After all, there is less information given, and it is difficult to think about the problem-solving ideas.

Yun Yan said: "An IMO (International Olympiad) question in 88."

Yu Ziheng froze for a moment, then nodded: "Yes, you did?"

Yun Yan: "I've seen it, but I haven't done it."

This is a legendary question. Some contestants did it back then, but the experts didn't write the answer within the stipulated time.

Xu Qianqian said: "It doesn't matter if you can't figure it out. The teacher said that this is a competition question. If you write it, you can ask him to get chocolates. If you can't answer it, don't think about it. Competition questions are a waste of time for most people."

Xu Xingli: "It's the law of proof."

Yu Ziheng was startled: "Why are you also in the car?"

Xu Xingli was so angry that he came out with a hammer and beat it up: "He didn't recognize anyone when he got in the car, right? The co-authoring competition question passed me directly to Yun Yan, right?"

Yu Ziheng begged for mercy while clutching his head: "No, I mean Xu Qianqian——I didn't know you two were sisters."

Xu Qianqian: "..."

Seeing Xu Xingli stop, Yu Ziheng breathed a sigh of relief, and said, "Xu Qianqian and I are classmates in junior high school, and she collects homework every day..."

He made up for it almost normally, and turned to ask Xu Qianqian, "Are you in the No. [-] Middle School next door now? How did you do in the monthly exam?"

Xu Qianqian was silent for a long time before whispering, "I'm in the same class as you."

Yu Ziheng was dumbfounded, he flattered the horse's leg, he really didn't pay attention to who was in the class.

Xu Xingli looked at Xu Qianqian who was so wronged that she was about to cry, and handed her the hammer in his hand: "I can borrow it from you."

Xu Qianqian shook her head: "Forget it, I can't do anything to beat someone..."

Xu Zhiyuan nodded in agreement: "That's right, fasten your seat belt and don't fight around in the car, it's not safe."

"I told you not to bring too many children home." Xu Xingli beat Yu Ziheng again with the air hammer, and then handed the small air hammer to Yun Yan, "Deflate it for me, stack it."

Yun Yan: "You might still use it later."

Xu Xingli: "And next time I will use a real hammer."

Yu Ziheng trembled, and asked Luo Jiamao in a low voice: "Is your deskmate so hot-tempered?"

I didn't think she had such a big temper before, at least she was reasonable—although she always said some wrong reasons.

Luo Jiamao: "My deskmate is a podium now, I didn't expect that."

Yu Ziheng patted him on the shoulder with sympathy: "...Thank you for your hard work, brother."

He felt that Luo Jiamao probably couldn't stand being beaten every day, so he asked the teacher to suggest that he move to the edge of the podium.

Luo Jiamao, who was once a school bully, was reduced to being beaten every day by Xu Xingli's stingy hammer, who could bear it?

It's like how he was once a student god, but was crushed by Xu Xingli in all aspects, and was forced by her to apologize in front of the whole school——

"How about we unite to overthrow her tyranny?" Yu Ziheng whispered to Luo Jiamao.

Luo Jiamao rolled his eyes and ignored him.

Three seconds later, the 100T jackhammer that hadn't had time to deflate returned to Xu Xingli's hand, and beat Yu Ziheng violently.

Yun Yan sat beside him, looking as if he had expected it.

A carload of children came home, Xu Zhiyuan asked them to do their homework in the living room.

Xu Xingli threw his schoolbag aside, took Yun Yan's draft book and pen from the table, and tried to write the answer to the competition question just now.

The reason is very strange, it is a task issued by the system, let her solve this problem, and reward her with [-] points.

She tried to wake up the system, but there was no response. She confirmed that the system was still in a dormant state. This task seemed to be arranged by the system early in the morning.

Xu Xingli was a little confused about the system's mission release mechanism and reward points. It should be a coincidence that Yu Ziheng followed Luo Jiamao into the car. Could it be that this kind of mission was triggered by Yu Ziheng handing in the questions?

First, suppose k is not the square of a certain positive integer. If a=b, then k=1 is calculated, which contradicts the assumption.

If a, b are not equal, set a>b>0...

Xu Xingli finished the proof process within 10 minutes, almost half a page of draft paper. She handed the process to Yu Ziheng and asked, "Are there any other questions?"

Yu Ziheng: "There are two competition papers, you can read them, but don't write them, the teacher left them for me to write - forget it, you can write them if you want, I'll ask the teacher for them tomorrow."

She took a look at the papers, a physical paper and a math paper, this time the system task was not triggered, she just glanced at it, then returned the papers.

Xu Qianqian was puzzled: "Don't you have homework in Class 15?"

Of the five people present, there were only two of them, the students in Class [-], doing their homework obediently. Yun Yan was holding a scratch paper and didn't know what he was writing, and Luo Jiamao was even more outrageous, holding a pencil and drawing on the side.

Xu Xingli: "I'm done."

Yu Ziheng tentatively asked: "I can hand in the competition papers in two days, why don't we play puzzles first?"

Xu Qianqian: "..."

It turned out that there were a table of people, only she had to do homework.

"Write." Yun Yan handed the draft to Xu Xingli. On it was a proof question he had just written. The question was much longer than Luo Jiamao's——

Let n≥3 be a given positive integer, C1, C2, ..., Cn are unit circles with a radius of 1 on the plane, and the corresponding centers are denoted as O1, O2, ..., On, assuming that any straight line at most Two unit circles intersect or are tangent, to prove...

Xu Xingli froze for a moment, pointed to the strange ∑ symbol on the ground and asked, "What is this?"

Of course she knew what it was, but she couldn't reveal it, it was a super topic, she shouldn't know this kind of thing now.

Yun Yan: "Summation symbol."

Xu Xingli read the title again and said frankly, "I don't understand."

"Can I take a look?" Yu Ziheng was a little curious about how difficult the topic even Xu Xingli could not understand.

Yun Yan didn't seem to hear him, so he took the notebook back, turned a page and said, "Then change the question."

Yu Ziheng looked at the calm Luo Jiamao with bright eyes: "Is their family so studious? Brother, I misunderstood you before. I didn't expect you to be a studious person."

Luo Jiamao: "..."

No, he is calm only because he simply knows that it is not surprising that this family will come up with any puzzles. After all, Xu Xingli took out the puzzle of hell two days ago...

Xu Xingli held down Yun Yan's hand that was about to write the question: "What strange desire to win has arisen again?"

Yun Yan: "You wrote the questions he gave, but not mine."

Xu Xingli was speechless: "That's a question given by his teacher."

Yun Yan nodded thoughtfully: "Understood, I will give you a question given by my teacher."

Xu Xingli watched helplessly that he was about to write calculus and linear algebra, so he quickly stopped him: "It's all about super-class!"

Yun Yan: "Running boats? Chickens and rabbits in the same cage?"

Xu Xingli: "...That's an elementary school problem, right?"

Yun Yan frowned, thinking about the difference between junior high school math Olympiad questions and elementary school math Olympiad questions.

Yu Ziheng wrote a fill-in-the-blank question on the paper and handed it to Yun Yan for reference: "The junior high school Olympiad question looks like this."

20222022^2-20222021^2=______.

Xu Xingli took a look, she knew this question, using associative law, it becomes a^2-b^2=(a+b)(ab), here ab=1, so the calculation is quite simple.

Yun Yan nodded, wrote down 20222022^2+20222021^2, and handed it to Xu Xingli.

Xu Xingli: "...Your difficulty has changed, right? You should pass this kind of question to the computer instead of me."

Yun Yan shook her head: "Ordinary computers don't count."

Xu Xingli: "..."

This kind of question is handed to the computer, and the computer thinks it is super class!

Resigned to her fate, she took out the draft paper, made a hard calculation, and secretly thought that she must find a chance, Dark Sha Yunyan.

Yu Ziheng expressed that he liked this kind of occasion very much, and wrote a question on the draft paper, and handed it to Xu Qianqian: "Come and try?"

Xu Qianqian: "..."

She could see that she couldn't stay in this house any longer, and it was the first time that her IQ was crushed by her peers.

What did these monsters eat and grow up?

The author says:

喻子珩递给许茜茜的题：S=15+195+1995+19995+……+199…95（44个9），S后四位数的和等于多少？

The first two math questions in this chapter are all IMO. The question in Zuohua is a fill-in-the-blank question in junior high school Olympiad. You can try it (Star Eye)

I'm running late so I'll keep writing Gagen!