Reba: My dating partner in the dating show is a super rich man!

The question on the treasure chest that Zhao Xinxin found was.

The purchase price of the product is 50 yuan per piece, and the selling price is 60 yuan per piece. 200 pieces can be sold each month. If the price of each product increases by one yuan, 10 pieces will be sold less each month (the selling price of each product cannot be higher than 72 yuan). Ask at what price of each product can the maximum profit be obtained each month? What is the maximum profit?

The question is not difficult. You just need to write down the equation of the quadratic function and apply the vertex coordinate formula.

Xie Yu has a strong memory and does not need to write at all. He has calculated it in less than 30 seconds after reading the question. The answer to this question is the selling price of 65 yuan and the maximum profit is 2250.

The password lock is a four-digit number, so the answer should be 2250.

Liang Feiran naturally cannot be as good as Xie Yu. He needs to write down the formula, simplify it step by step, and then apply it into the formula.

However, this process does not seem to be smooth.

Liang Feiran had forgotten how to find the maximum value of a quadratic function and the formula for vertex coordinates.

Xie Yu thought: This problem is difficult for him.

Just at this time, Reba brought another treasure chest that needed to be decrypted, and Xie Yu immediately turned around to help Reba solve the problem.

He thought that Liang Feiran was unlikely to solve this problem anyway, so let's torture him for a while!

Zhao Xinxin was a little unhappy when she saw Xie Yu directly abandon her problem and turned to help Reba.

She is obviously very beautiful, but why is Xie Yu only good to Reba!

And Reba, didn't you see Xie Yu was helping her solve the problem!

He even ran over to cut in line.

So rude!

Zhao Xinxin glared at Reba with some resentment.

Reba didn't notice Zhao Xinxin's eyes.

She was studying the problem on her treasure chest very attentively.

This problem gave three groups of time.

She really couldn't see what the time had to do with the password.

It took Xie Yu only a few seconds to figure out the answer.

"Reba, how about I tell you how to solve it, and you try to solve it yourself?"

Xie Yu wanted to give Reba some game experience and participation.

Lest she think that this game is boring in addition to scary.

"Okay, then tell me how to solve it!"

Reba herself was actually quite curious about how to solve this problem.

"Look, for example, the first group of 9:00, what should the shape of the hour hand and minute hand on the clock look like?"

Xie Yu picked up a pen and patiently explained to Reba.

Reba gestured, "It should be a right angle like this."

"Yes! Then you combine the remaining groups of time corresponding to the pointer graphics, and see what it will form?"

When explaining the problem, the bodies and heads of the two people unconsciously moved closer to each other, leaving only a very small gap, which seemed very intimate.

The audience in the live broadcast room immediately started to laugh.

[This scene really looks like a boyfriend explaining a question to his girlfriend, and it instantly brought me back to high school]

[These two people are a perfect match, talented and beautiful, a perfect match! ]

[Teacher Xie, when you taught us, it was not like this]

As Xie Yu's graduation school was exposed, those alumni who had seen him in school before, after knowing the news that he participated in the dating variety show, also ran to watch the live broadcast.

They all wanted to see how the high-cold school hunk chased girls back then?

[In front, what was Xie Yu like when he was in class? Curious◉‿◉]

[He was so fierce, we never saw him smile, let alone speak in such a gentle tone]

[At that time, the girls in our class were always in pain and happiness, wanting to take his class, but also afraid to take his class]

[The key point was that he was only 19 years old at that time, younger than most of our classmates (dog head~)]

[It's so interesting, I also want to take Teacher Xie's class, but it's a pity that I can't get into Huaqing! 】

[Me too, woooo~~~]

The girl who replied to the message thought, even if you pass the exam, you probably won't be able to take Xie Yu's class.

When Xie Yu taught them, he was also a student.

But at that time he was already studying for a doctorate.

The teacher who taught them advanced mathematics that semester had an operation because of illness and needed to rest at home for a while.

So they asked Xie Yu to teach them for a while.

Later, the teacher recovered, and Xie Yu stopped teaching them.

However, because Xie Yu was so strong in all aspects, they all admired him very much.

So even if Xie Yu no longer taught them, they still called him teacher and were proud of the fact that Xie Yu had taught them a few classes.

OftenIt was used as a capital to show off to other alumni.

After they graduated from college, Xie Yu also finished his studies and left school.

They hadn't heard from him for more than a year.

They never expected that one day, they would see him on a dating show.

This feeling was too magical!

——

Zhao Xinxin waited for Xie Yu to finish explaining the problem to Reba, and immediately came over.

"Xie Yu, can you also teach me how to solve this problem? I also want to try to solve it myself."

Xie Yu leaned back and deliberately distanced himself from Zhao Xinxin.

"Do you know quadratic functions?"

Zhao Xinxin, who only has a secondary technical school education, shook her head.

If she knew quadratic functions, she wouldn't have gone to secondary technical school that year.

"Then forget it! You can't solve this problem even if I give you ten hours."

Xie Yu: You don't even know what a quadratic function is, where do you want me to start teaching!

The students that Xie Yu had taught before in the live broadcast room immediately laughed.

[Puff~, haha~, Teacher Xie, how can you still speak so bluntly! ]

[Zhao Xinxin: What are you talking about! ]

[This is Teacher Xie! As sharp-tongued as ever]

[Teacher Xie, I thought you had changed, but you haven't changed! ]

Zhao Xinxin didn't expect Xie Yu to be so disrespectful, and the whole person was embarrassed.

Liang Feiran saw the opportunity and immediately said enthusiastically.

"Xinxin, I know quadratic functions, let me teach you!"

Although he couldn't solve the problem, he still knew what quadratic functions were.

In order not to let his face fall to the ground, Zhao Xinxin had to agree.

Then the two sat together.

Liang Feiran talked to Zhao Xinxin non-stop.

Zhao Xinxin didn't understand at all, but he could only listen to it.

A few minutes later, Reba solved her own problem.

"Xie Yu, the password is 948, right?"

"Yes!" Xie Yu nodded with a smile.

"You solved it so quickly, you are amazing!"

Reba smiled shyly.

Xie Yu's students in the live broadcast room couldn't stand it anymore.

[Teacher Xie, you are too hypocritical! ]

['Amazing', haha~~, it turns out that being able to solve calculus is not amazing, being able to draw clock graphics is amazing]

[Teacher Xie, I solved such a difficult math proof back then, and I never heard you praise me]

[Is this amazing? Then what should you call your resume of winning the gold medal in the International Mathematical Olympiad at the age of 13, the gold medal in the International Physics Olympiad at the age of 14, solving world-class math problems at the age of 21, and being hired as a full professor by Huaqing University at the age of 22? ]