Let a, b, c, and d be real numbers, and find the minimum value of a²+b²+c²+d²+ab+ac+ad+bc+bd+cd+a+b+c+d.

After reading the question, the person with whom he or she took out a pen and began to write the scratch paper.

The game was quiet for a while, and even Lin Lu, who was sitting in the stands, could feel the tension in the field.

"I hope the first kill is Senior Song Beixin."

"It's Senior Jiang Ye."

Ignoring the people sitting below her and next to her, she looked at the question on the screen and read it...... Suddenly I felt like my head was bigger...... Lin Lu completely admitted the fact that he was a scumbag.

"The atmosphere is so tense now, this question is relatively simple, but in this tense atmosphere, it will be a little accurate and timely calculation" Before the word difficulty was spoken, a bell was heard on the playing field.

The person who rang the bell was not the person in their mouth, but the Si Jing in Lin Lu's mouth.

The narrator, Mr. Wang, said, "Please ask Si Jing from Mingli Middle School to answer the correct answer within 10 seconds. ”

Si Jing: "-2/5." ”

After hearing his answer, Lin Lu smiled proudly, as if she had done the right thing.

After he finished speaking, the arena fell silent, and most of the spectators did not know whether the answer was correct or not, and waited for the referee to give the order.

Three seconds later, the referee raised his card.

The narrator, Mr. Wang, took a breath and said, "Congratulations to Mingli Middle School, add ten points." ”

Si Jing from Mingli Middle School won the first kill.

Si Jing took the lead in scoring ten points, which made the audience quiet, and the leaders were shocked by Si Jing's calculation speed!

The students in the Mingli stand were the first to relieve, and all the staff stood up and gave Si Jing their warmest applause. The commentator, Mr. Zhang, was relieved by their applause and also stood up and applauded.

Si Jing's teammates said, "First question, won? ”

"Hmm." It's not a difficult question. Si Jing didn't say it in the second half, he felt that if he said it, he would definitely be beaten by them.

The team is friendly. Si Jing's teammates thought in unison.

At this time, everyone didn't know that they were about to enter the horror called Si Jing.

"Please look at the second question."

The second question is a simple high math question, all the staff bowed their heads and began to answer the question, and before a minute had passed, the bell rang on the field.

Everyone looked in the direction of the bell and saw that Si Jing rang the bell again.

Fengyun Middle School: "..."

Qingyang Middle School: "..."

Ivy League High School: "..."

Teacher Wang, the narrator of Fengyun Middle School, was a little unstable, but continued to explain: "Please ask Si Jing from Mingli Middle School to answer the correct answer within ten seconds. ”

“√15。”

The commentator, Mr. Wang, glanced at the referee's sign and said, "Congratulations on the correct answer, Mingli Middle School has scored another ten points." ”

The audience cheered.

After taking a deep breath, the contestants from other schools thought: no hurry, there is another question.

Lin Lu turned his head to the side and snickered when he saw Si Jing's confident face.

The teachers of Mingli Middle School in the audience discussed the scene with two questions.

"Si Jing in the third year of high school is a myth of our school, the first in the city all year round."

"Then why did he keep taking second place for the first two years!"

"Shhhh It is said that our principal has been asking this kid to put some water, so as not to hurt the harmony of the four schools, so that he takes the second place every year...... But I don't know what's going on this year? ”

"Needless to say, it's the last league! If you want me to say that our students are of high level, why don't you let them show it! The teacher's voice stopped, and something suddenly came to his mind that surprised him.

Unless he's done with advanced math in college by now.

But this thought was dispelled by him, it was too reluctant, and if that was the case, there were only eight questions left......

As it turned out, his conjecture was not wrong.