[2: A, B, C, and D are all positive integers, and logab=3/2, logcd=5/4, if a-c=9, then b-d=......]

Tut-tut!

Good guys, that's good guys.

This is really a high level of difficulty, and it feels like it is really going to rub everyone's IQ on the ground!

From the question, we can easily get a^3/2=b,c^5/4=d, so a=(b/a)^2,c=(d/c)^4, so a|b,c|d, and since a-c=9, (b/a)^2-(d/c)^4.

i.e. (b/a+d^2/c^2)(b/a-d^2/c^2)=9.

This equation must be solved by everyone, right?

You only need to do the verbal math to get a=25, b=125, c=16, d=32.

So b-d=93.

Let's go to the next question.

This third question examines the area of a triangle formed by the focal points of two ellipses and the points on the ellipses.

The fourth question examines the problem of dividing the extremum of the number of elements and the sum of elements in the decimal system.

The fifth question examines the monotonicity of functions and the ratio of function sizes in monotonic intervals.

Question 6 examines the definition of imaginary numbers......

……

The summary is just two words, simple.

It's not difficult, it's stressful, you don't even need to think, you can see the answer at a glance.

There are eight fill-in-the-blank questions in a row, with an average of only 10 seconds for one and 80 seconds for eight questions, which is more than one minute.

"Hey, it's boring!"

"With such a question, it can also be used for competition, and the teacher of this paper is inevitably too incompetent."

"Even Teacher Li Daxian is not as good as Teacher Li in the morning, and compared with Teacher Ge Tianxing, there is an unknown grade difference."

"On weekdays, any fill-in-the-blank question given to me by Mr. Ge Tianxing can kill this competition question countless times in seconds."

"Don't say it's me, it's the third and fourth and the fat man, I should be able to score seventy or eighty points, right?"

"Well, be conservative, it should be okay to pass, after all, they have made a lot of progress recently."

"Even if you don't get a master, it shouldn't be far away, but you haven't passed the exam yet."

"It may be difficult for them to do this question, but they can't stand enough time, a total of three hours, a question can't be solved in one minute, and there are always signs in ten minutes, right?"

Lin Bei secretly thought that he could be said to be extremely disappointed with the competition papers.

Then, he looked at the last three questions, "I hope this one will be a little more difficult!" ”

"Otherwise, the three-hour roll will be completed in less than ten minutes, which is really tasteless."

"Especially since this is my first time, why do I have to hold on to it for thirty minutes, right?"

Lin Bei sighed, and looked at the ninth question, which was also the first to be answered, and saw ......

[9:3/2≤x≤5, proving inequality 2√(x+1)+√(2x-3)+√(15-3x)≤2√19.] 】

Lin Bei: "%¥#@#¥%......"

The heart is a full thirty seconds.

It's not because he thinks it's difficult, it's not that he can't understand it, and it takes a full thirty seconds.

And sheerly, he was completely disappointed.

Even, he's going to collapse.

Is it really necessary to put this pediatric inequality into competition? Or answer the first question?

But if you read more books and brush a few more questions on weekdays, you should know that (a+b+c+d)^2=a^2+b^2+c^2+d^2+2(ab+ac+ad+bc+bd+cd)≤4(a^2+b^2+c^2+c^2+d^2), so a+b+c+d≤2√(a^2+b^2+c^2+d^2), and take the equal sign if and only if a=b=c=d.

Just set a=b=√(x+1).

c=√(2x-3)。

d=√(15-3x)。

Then substitution, and the inequality is easily proved.

Does it take a minute?

Probably not, right?

Lin Bei didn't calculate the time, anyway, he wrote from the beginning to the end in one breath, and then looked directly at the next question.

Then another minute, then the next question, and then another minute, Lin Bei still wanted the next question.

But suddenly his hand stopped, and the pen fell.

Don't ask why.

Just because ......

There are three questions in total, and he has already done them, and this volume is at the end, and there are no questions behind!

Seeing this scene, Lin Bei felt indescribably lonely in his heart, and even couldn't help but bow his head and sigh alone.

Hey, what's the wrong word?

Especially when he thought that he had been looking forward to it for so long, but in the end it ended like this, Lin Bei really couldn't accept it.

Seeing this scene, a female invigilator teacher who was nearly forty years old immediately walked over and said with gentle concern: "This classmate, what's wrong with you?" You seem to be very uncomfortable, do you want to take a break before doing it, and don't rush if you have enough time? ”

It's worth mentioning.

The female teacher had been paying attention to Lin Bei for a while, and even saw Lin Bei as soon as she walked in.

After all, Lin Bei's appearance is so powerful, he can be said to stand out from the crowd, and it is difficult not to attract attention.

But what this female teacher never expected was that just a few minutes after the exam started, Lin Bei couldn't stand it, looking at her sad face, her typical mentality was about to collapse!

In previous years' Olympiad exams, there were many students who broke down and even cried halfway through the exam.

Even if these students are the top students in major schools, they are all top students.

But top students, if they haven't experienced special training, are really not enough in front of the Olympiad.

So generally speaking, it is not surprising that the teacher has a sad face on the student's face halfway through the exam.

But at the moment, it's not half of the test!

The three-hour exam time is less than ten minutes now, no, no, no, it seems that only five minutes have passed.

After only five minutes of the exam, Lin Bei couldn't stand it, which has to be said to surprise the teacher.

"Isn't it true that good looking students can't get grades? But if the results are not good, it is impossible for their school to let them participate in the preliminary round of this Olympiad? ”

"Or is it that the papers in the preliminary round are too difficult, so difficult that this doll can't do a single question, so she is so uncomfortable, so painful, and about to collapse when she just starts the exam?"

The former is most likely impossible.

After all, all of the people who can participate in the competition are the proud sons of heaven who are carefully selected from various schools.

So Lin Bei's results should still be okay.

It's just that the questions in this competition are too difficult and beyond Lin Bei's strength, so the performance is so painful.

Come to think of this.

The teacher immediately reminded: "This classmate, it doesn't matter if you can't do it, just do your best, after all, if you can't do it, others may not be able to do it." ”

"We must be calm, don't be in a hurry, and this question will not be done for the time being, you will finish everything you can...... Hey? Have you finished question 11? ”

The conscience of heaven and earth, she originally just looked at Lin Bei's good appearance and temperament, and she should be a good student.

So, I just want to mention it on point.

This is not a violation of the discipline of the examination room.

After all, as an invigilator, it is also appropriate to guide the students' mentality to prevent extreme problems.

However, before he could finish speaking, he came to an abrupt end.

Just because ......

She actually found a very incredible scene, that is, Lin Bei actually finished the 11th question?

Like, it's just 11 questions, right?

In just five minutes, 11 questions were completed, what is this funny? Or is it very funny?

She didn't think that Lin Bei would be able to get all these 11 questions right in just five minutes, but she must have scribbled.

And this just proves that Lin Beizhi's state at this moment is not generally bad.

After all, just starting the exam and scribbling through and completing 11 questions directly, isn't this typical self-defeating?

"This person is estimated to be a contestant from the school below, that is, he looks very good, and his grades may be okay in his school, but there is too much difference with the above, as soon as he encounters this competition question, he immediately reveals his true form, and then his mentality collapses."

This is the teacher's subconscious cognition of Lin Bei.

But when Lin Bei heard her words, he sighed and shook his head: "Teacher, you misunderstood, I am uncomfortable and anxious, not because the paper is too difficult, but because it is too simple." ”

"I really don't know who made the paper, there is no freshness at all, and there is no challenge at all."

"What a waste of time!"

Female invigilator: "(๑ŐдŐ)b?? ”

what？？？

What did she just hear?

Lin Bei scribbled 11 questions in five minutes without saying anything, but he actually disliked the questions too simple?

It's not a mental breakdown, it's a brain that goes crazy, and you just start talking nonsense?

But the nonsense is still quite handsome, do you want to send it to rest quickly... What about infirmary treatment?