Friday, May 15, Nangang No. 2 High School Class 2 (2) classroom.

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

Shen Qi shook his head: "Watching a movie this Sunday? I don't have time, you really know how to pick time, on purpose!"

Chen Xiaoting looked left and right like a thief, and said, "Hey, can you be quieter?"

Shen Qi whispered slightly: "I'm really not free this Sunday, I'm going to participate in the provincial high school math league, and I've already signed up." ”

"Well, it's going to be the math league, next time, another day. Chen Xiaoting breathed a sigh of relief, but she was a little regretful: "But I only have half a day to free this Sunday, and I don't know when I will be next time." Shen Qi, I really appreciate you for tutoring me in math every day, I have made great progress in doing math problems now. I really want to treat you to a movie, or a meal or something, as a token of appreciation. ”

"They are all classmates, and you are my tablemate, don't say these cheesy words, hurt your feelings. ”

"Well, I'm vulgar, I wish you a victorious start and a triumphant return in the math league!"

"Chen Xiaoting, what did you just say, invite me to dinner? Then you can invite me to a light meal. ”

“......”

Shen Qi and Chen Xiaoting came to the off-campus chain Chinese restaurant, and the business in the store was booming and crowded at lunchtime, and most of the customers were nearby students.

Of course, Nangang No. 2 Middle School has a canteen, but the big pot of rice in the canteen is unpalatable, and the students' lunch is either eaten at home or solved outside the school.

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

"Shen Qi, there are three kinds of packages, spicy chicken thigh rice + overlord flower keel soup, potato beef brisket rice + American ginseng black chicken soup, salted fish eggplant rice + American ginseng black chicken soup, which one do you eat? Chen Xiaoting operated the mobile phone and asked.

"Don't rush to order just yet, there's a bug here. Shen Qi has been staring at the order information screen in the store.

Chen Xiaoting was puzzled: "BUG?"

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

"Pretty girl, welcome, what do you want?" asked the clerk warmly.

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

Shen Qi stepped forward and walked to the counter and said, "Your spicy chicken thigh rice + overlord flower keel soup package is 30 yuan, potato beef brisket rice + American ginseng black chicken soup package is 28 yuan, and salted fish eggplant rice + American ginseng black chicken soup is 25 yuan, which is actually a combination of three main meals and two stew cups." ”

The clerk smiled and said: "That's right, this classmate is awesome in mathematics, you and this beautiful girl are together, may I ask which package? ”

Shen Qi said unhurriedly: "Your menu information shows that the spicy chicken thigh rice is sold for 22 yuan, and the unit prices of potato and beef brisket rice and salted fish and eggplant rice are 20 yuan and 15 yuan respectively. ”

The clerk still maintained a professional smile, but was already a little impatient: "May I ask you to buy the main meal alone without a stew cup, right?"

"No, my classmates and I came to your house to consume, mainly to drink soup, and your stew pot is good. ”

"What kind of package do you need?"

"Before I ordered, I had to figure out the unit price of the two stew cups. Although you didn't publish the unit price of the stew pot, I was able to solve the unit price of the dragon bone soup and the black chicken soup with American ginseng through a simple system of equations. Shen Qi looked at the menu screen again, and had already calculated the result.

"......" The clerk stopped laughing, and said in his heart that there is something wrong with you?

Chen Xiaoting was confused, Shen Qi, I invite you to lunch, don't do anything!

Shen Qi said seriously: "Here I set the unit price of the dragon bone soup of the overlord flower as x, and the unit price of the black chicken soup with American ginseng as y, and get three one-time equations, which are combined into a system of one-time equations. ”

"Through a not complicated calculation, I got an x value, that is, the unit price of the dragon bone soup is 8 yuan, OK, there is no problem with this. ”

"But it's worth noting that y has two values, 8 and 10. ”

"That is to say, your American ginseng black chicken soup can be sold for 8 yuan a cup, and can be sold for 10 yuan a cup, in a one-time equation system, the same y cannot appear two real number roots, which deduces another question, that is, whether the unit price of your American ginseng black chicken soup is an imaginary root? 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 scolded in his heart, I'll tell you an MMP! If I can solve the imaginary root, do I still need to sell fast food here?"

"Damn, Xueba!"

"Capture a wild school bully alive!"

"Classmate, which school are you, the second middle school or the seventh middle school? Make a friend and get a CP, I sweep you or you sweep me?"

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

"Poof~" Chen Xiaoting, who was still confused just now, snickered, 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 is quite keen, this kind of detail is not many normal people would deliberately pay attention to, but Shen Qi noticed.

"Yes, why does the unit price of your stew pot have two real roots?"

"It's not scientific!"

"Black shop?"

"We need a reasonable explanation!"

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

"Call the police, please fight the demon spirit? Then please help me transfer the demon spirit. ”

The surrounding melon-eating students attacked it, and there was chaos in front of the ordering table.

"Students, please calm down!"

"Calm down!

"Don't make trouble, classmates, you are all cultural people who have read books!"

The clerks and girls were in a hurry, and no one could answer Shen Qi's math problems, all they could do was try to appease the half-grown bear children.

At this critical moment, the store manager stepped forward: "There is no imaginary root in our store, and the unit price of each stew cup is only one real number!

"Store manager, in fact, what I want is an Abel group explanation, can you understand it?" Shen Qi likes to communicate with professionals.

The store manager couldn't answer Shen Qi's question, but he had already discovered the root cause of the chaos, in fact, it was the difference between 2 yuan in their American ginseng black chicken soup.

"The unit price of all the stew cups in our store is only one real number, which is 8 yuan! The price information of salted fish and eggplant rice + American ginseng black chicken soup is displayed incorrectly, not 25 yuan, but 23 yuan! Customers who have purchased this package can ask us to refund 2 yuan with a small receipt!" The store manager reacted quickly and immediately took emergency measures.

This explanation is barely reasonable. Shen Qi nodded, and said to Chen Xiaoting: "Let's both order salted fish and eggplant rice + American ginseng black chicken soup package, counting the correction value and preferential value, we can save a total of 9 yuan, that is, 8.2% off." Let my sister invite me to dinner as a man, after all, I'm embarrassed, I can save you a little. ”

"Okay, in order to get a few dollars cheaper, you actually moved out the real number of imaginary roots, Shen Qi, you really fight!" Chen Xiaoting scanned the code with her mobile phone and bought two salted fish and eggplant rice sets.