On Friday, May 15, the classroom of Class 2 (2) of Nangang No. 2 Middle School.

After the last class in the morning, Chen Xiaoting said to Shen Qi in a low voice: "Shen Qi, are you going to watch a movie this Sunday?"

Shen Qi shook his head: "Watching a movie this Sunday? I'm not available. You really know how to choose time, do it on purpose!"

Chen Xiaoting looked around like a thief and said angrily: "Hey, can you just say a little bit more?"

Shen Qi said a little less: "I really don't have time this Sunday. I'm going to participate in the provincial high school mathematics league. I've signed up."

"That's the case, then the math league must be the priority. Next time, another day." Chen Xiaoting breathed a sigh of relief, but also felt a little regretful: "But I only have half a day of free time this Sunday, and I don't know when next time will be. Shen Qi, I really thank you for tutoring me in math every day. I'm making great progress in doing math problems now. I really want to invite you to watch a movie or have a meal or something to show my gratitude."

"All classmates, you are my deskmate again. Don't say these cheesy words, it hurts your feelings."

"Okay, I'm vulgar. I wish you a victory and a triumphant return in the Mathematics League!"

"Chen Xiaoting, what did you say just now, treat me to a meal? Then you can treat me to a meal."

“…”

Shen Qi and Chen Xiaoting came to the off-campus chain Chinese restaurant. During lunch, the store was booming and crowded, and most of the guests were students nearby.

Of course, there is a canteen at Nangang No. 2 Middle School, but the big pot rice in the canteen is unpalatable. Students either eat lunches home or solve them outside the school.

Shen Qi and Chen Xiaoting lined up to wait for orders. Chen Xiaoting took the initiative to stand in front of Shen Qi, and she invited this lunch.

"Shen Qi, there are three set meals, spicy chicken leg rice + oxin flower dragon bone soup, potato brisket rice + citi ginseng black chicken soup, salted fish eggplant rice + citi ginseng black chicken soup, which one do you eat? I can order food on my phone, let's pay for it together, it's five yuan cheaper." Chen Xiaoting asked while operating the phone.

"Don't rush to order food first, there is a bug here." Shen Qi kept watching the ordering information screen in the store.

Chen Xiaoting was puzzled: "BUG?"

The team continued to move forward, and Chen Xiaoting came to the ordering table.

"Welcome to the beautiful girl, what do you want?" the clerk asked enthusiastically.

Chen Xiaoting turned around and asked Shen Qi: "I want potato brisket rice + Citigang ginseng black chicken soup set meal, what about you?"

Shen Qi stepped forward and walked to the counter and said, "Your spicy chicken leg rice + oxin flower keel soup set is 30 yuan, potato brisket rice + Citigaret ginseng black chicken soup set is 28 yuan, and salted fish eggplant rice + Citigaret ginseng black chicken soup is 25 yuan. This is actually a combination of three main meals and two stew pots."

The clerk smiled and said, "Yes, this classmate is awesome in mathematics. You are with this beautiful girl. Which package is the best package? There is a discount on mobile payment."

Shen Qi said slowly: "The information of your meal brand shows that the single sale of spicy chicken leg rice is 22 yuan, the unit price of potato brisket rice and salted fish and eggplant rice is 20 yuan and 15 yuan respectively."

The clerk still kept a professional smile, but was a little impatient: "Would you like to buy the main meal without adding a stew pot?"

"No, my classmates and I come to your house to consume, mainly to drink soup. Your house has a good stew."

"So what kind of package do you need?"

"Before ordering, I must figure out one problem, that is, the unit price of the two stew pots. Although you have not announced the unit price of the stew pots, I can solve the unit price of the stew pots through a simple system of equations." Shen Qi looked at the dining brand screen again and had thoughtfully calculated the results.

"..." The clerk stopped smiling and thought to himself, "What's wrong with you?"

Chen Xiaoting is confused. Shen Qi, I'll treat you to lunch, don't make trouble!

Shen Qi said seriously: "Here I set the unit price of Bawanghua Dragon Bone Soup to be x, and the unit price of Citigarbha Wu Chicken Soup to be y, and I get three primary equations and combine them into a system of primary equations."

"Through the uncomplicated calculation, I got an x ​​value, that is, the unit price of the Tyrannosaurus Dragon Bone Soup is 8 yuan, OK, there is no problem with this."

"But it is worth noting that there are two values ​​of y, 8 and 10, respectively."

"That is to say that your family's Citigaret ginseng chicken soup can be sold for 8 yuan per cup and 10 yuan per cup. In a system of equations, two real numbers cannot appear in the same y. This leads to another question, that is, does the unit price of your family's Citigaret ginseng chicken soup have imaginary numbers? What is the truth? Please tell me, as a consumer, I have the right to know the truth."

"I...I..." The clerk was speechless. He cursed in his heart, "I'll tell you an MMP! If I can solve the problem, I'd have to laugh and sell fast food here?"

"Damn it, a top student!"

"Catch a wild student alive!"

"Student, which school you are from, No. 2 Middle School or No. 7 Middle School? Make friends and have a CP, will I scan you or will you scan me?"

There were many students queuing up to buy meals, and Shen Qi was instantly watched.

"Puff~" Chen Xiaoting, who was confused just now, laughed secretly. What Shen Qi said seemed to make sense. Why can the same stew pot deduce two different unit prices? What is the truth? Shen Qi's observation ability is quite keen. Few people will deliberately pay attention to such details, but Shen Qi noticed it.

"Yes, why do you have two real numbers of stew pots in your house?"

"This is unscientific!"

"Black store?"

"We need a reasonable explanation!"

"Hey, is the 12315 Consumer Protection Association? There is a black store at No. 233 East Eighth Street, Tianhe. I want to call the police!"

"Call the police and kill Yaoyaoling? Then please help me transfer Yaoyaoling."

The surrounding students attacked him, and there was chaos in front of the ordering table.

"Students, please calm down!"

"Calm down! Reason!"

"Stop messing around with classmates, you are all cultural people who have studied books!"

The clerk and the clerks were in a hurry, and no one could answer Shen Qi's math problems. All they could do was to comfort these half-large and not young naughty children.

At this critical moment, the store manager stepped forward: "There are no imaginary numbers in our store, and the unit price of each type of stew pot is only one real number! The display is wrong, and the package price information is displayed incorrectly!" After all, people who can be a store manager have a higher level of education.

"Shopkeeper, what I want is an Abel group explanation. Can you understand it?" Shen Qi likes to communicate with professionals.

I can't understand when I go to Abel group, do I need to beat up now? The store manager cannot answer Shen Qi's question, but he has discovered the root cause of the chaos. In fact, it is the difference between their 2 yuan Citigarette ginseng black chicken soup. In short, it's a handle that is caught by others. It's also very upset to think about it. What are you worried about if the Industrial and Commercial Bureau doesn't care about?

"The unit price of all the stewed pots in our store is only one real number, which is 8 yuan! The price information of salted fish, eggplant rice, Citigaret ginseng, black chicken soup is incorrect, not 25 yuan, but 23 yuan! Customers who have purchased this package can ask us for a refund of 2 yuan with a receipt!" The manager responded quickly and immediately took emergency measures.

"If you explain this, it's barely reasonable." Shen Qi nodded and said to Chen Xiaoting: "We both order salted fish, eggplant rice, Citigang, ginseng, black chicken soup set meal. Including the correction value and discount value, we can save a total of 9 yuan, which is 82% off. I'm sorry to ask the girl to treat me as a man to dinner. I can save you a little."

"Okay, in order to make a few dollars cheaper, you really work hard. Shen Qi!" Chen Xiaoting scanned the code with her mobile phone and bought two sets of salted fish eggplant rice.
Chapter completed!