Those who are good at mathematics are advanced, and those who are good at mathematics are suitable f

It's troublesome. Be patient and watch ...

Let x 1 x=t then (x 1 x) =x 1 x +2=t i.e. x 1 x =t -2

So the original formula is replaced by t then:

2 (t -2) 3t 1 0 solution t=-1 or.

When x 1 x=t=-1.

(1+x) x=-1

Re-move the term 1+x +x=0 and find no solution with the root formula.

When x 1 x=t=.

In the same way, find x=2 or remember to divide first and then move the term, and finally use the root formula).

Both sides are squared:

x = a x -2a x+a i.e. (a -1) x -2a x+a =0

When a is not equal to 1.

b 2-4ac=4a 0 shows that a quadratic equation has 2 identical or different roots (continue to discuss this later).

When a 1, according to the function image, the axis of symmetry is greater than 0 and x 0 is y, and it must be greater than 0, and you change the condition I said to a 1, a 1 or a -1

When a 1, the same is true for a unsolvable.

When a is equal to 1.

x = in summary: a 1 or a -1

Finally written a good pull, I hope you understand it!

1.Use the commutation method. x²＋1／x²+2-2=（x＋1／x）^2-2。

Therefore, the original equation can be reduced to: 2 (x 1 x) 2-3 (x 1 x) 5=0 Ling(x 1 x)=y, then there is 2y 2-3y-5=0, find y, and then find x.

2.There is a positive root, indicating a>0, then |x|=x, then the equation is x=ax-a, x=a (a-1)>0, so we get the range of a, i.e., a>1 or a<0.

There are many capable jobs. You can be a teacher, an IT clerk, a businessman, a business manager, and a math study.

1. Be a teacher. Graduates of mathematics and applied mathematics majors can go to primary school, middle school or university to become teachers, and in the normal category, mathematics majors are relatively easy to employ, and many schools recruit more mathematics teachers.

2. Be an IT employee. Mathematics and Applied Mathematics is a basic major and is the "parent major" of other related majors. Graduates of this major have an innate advantage if they want to "change careers" into careers such as scientific research data analysis, software development, and 3D animation production, and many graduates of mathematics and applied mathematics majors will work in the IT industry after graduation.

3. Do business. On Wall Street, many gold collars are math majors, such as financial mathematicians, who use mathematical ideas to solve financial problems.

Fourth, do business management. Although they graduated from mathematics majors, some graduates can enter enterprises to engage in management work, but the job requirements are relatively high and the competition is fierce.

5. Do research in mathematics and study mathematical knowledge.

The five characteristics of a person who is good at mathematics are as follows:

1.Strong thinking ability: Students with good math scores are not bad in logical thinking.

Logical thinking ability is a very important ability. When doing math problems, students with strong logical thinking skills can deduce the answers step by step through the known conditions, unknown conditions and implied conditions given by the questions. In order not to let their children lose at the starting line, many parents begin to cultivate their children's logical thinking skills from an early age.

Therefore, the sooner logical thinking skills are cultivated, the better.

2.Strong spatial imagination ability: Students with strong spatial imagination ability generally do not score badly in mathematics.

The learning of many knowledge points in mathematics requires spatial imagination ability. For example, in the study of three-dimensional geometry, the spatial imagination ability is poor, and we cannot imagine the combination and arrangement of figures. The formation of spatial imagination relies on the storage and mapping of actual images in the brain.

Some students' spatial imagination ability is poor, because the space storage is not enough, and the imagination is not rich enough in front of the rock, and they cannot imagine the spatial form of the figure. Therefore, students should see, listen, draw and operate more, and consciously improve their spatial imagination ability.

3.Sensitive to numbers: In the process of learning, we will meet students who are very sensitive to numbers, and many numbers can be remembered at a glance.

Students who are sensitive to numbers generally do not score badly in mathematics. The study of mathematics is inseparable from numbers, and we learn mathematics to deal with numbers. Sensitive to numbers, full of love for math, and the things we love will soon get into the groove.

Therefore, students who are sensitive to numbers generally do not score badly in mathematics.

4.Strong numeracy skills: Mathematics exams are inseparable from calculation questions, which are the easiest questions in mathematics papers, but they are the ones with the highest score loss rate.

What is the reason for this? In fact, this is mainly due to poor computing power. Students should improve their calculation ability, get out of the calculator in the process of doing problems, and calculate neatly, copy the numbers and symbols correctly, so as to avoid losing points due to calculation errors.

5.High Classroom Efficiency: Students with good math scores are very efficient in the classroom.

The classroom is the main place for students to acquire and receive knowledge. By improving the efficiency of the classroom, we will be able to digest and absorb more knowledge in the classroom. If you understand the knowledge points taught by the teacher in class, you will be able to write homework quickly after class, and you will have more time for practice, preview, and review.

Therefore, students with high classroom efficiency will not only score badly in mathematics, but also in other subjects.

The country that is most adept at learning the number of brothers and ears is France. Lagrange, Cauchy, Fermat, Fourier, Laplace, Monge. A large part of the mathematicians are French, and there are very few mathematicians in China.

I personally think that this is not necessarily, but also depends on the talent and intelligent fighting intelligence of some people, some Chinese are very good at mathematics, but some Huai Pinpins Chinese are not good at it.

Personally, I think that not all Chinese are good at mathematics, and learning mathematics well has nothing to do with whether they are Chinese, but only related to their own interests.

Not all Chinese are good at mathematics, but mathematics is a very important subject in China, and children have to learn mathematics from an early age.

No. There are many kinds of Chinese. Different people have different talents, some people are good at learning Chinese, some people are good at learning mathematics, and it still varies from person to person.

No, it's just that some people are not good at math. China's academic status in the international community is mathematics in addition to the national language, and China's mathematical achievements are not low, so not all Chinese are not good at mathematics.

No, many young people nowadays are not sensitive to mathematics and are not good at it.

No. Some people have a very low IQ and are not strong in logical thinking, so they are not good at mathematics.

No, being good at math requires talent, and not everyone has the same way of thinking, so not all Chinese are good at math.

1.Flexible:

Flexibility is to face a burst of thinking and association to solve a problem.

For example, when you see an inequality to be proved, you need to think of mean inequalities, Cauchy inequalities, etc., and maybe you need to think of derivation, induction, and equal cycle inequalities? Wait a minute. This kind of association requires the thinker to have enough understanding of the previous theorems and some examples, so that he can think of them in time when he sees a problem that may be related to them.

When it comes to flexibility, the gap between people is twofold. First, accumulation. Second, the ability to associate.

2.Efficiency: Efficiency refers to the speed at which different people think or give up on the same problem when trying the same way.

For example (this example is stupid, meaning) see a simple proposition: if a number is not 1 then it is 2. If we want to try to prove it by the anti-case method, then we have to think about what conditions we have if the proposition is not true.

We know that there is a number, it is neither 1 nor 2, there is no contradiction, then this method will not work. Everything mentioned above is a process in the mind of the thinker, and the concentration, agility, proficiency, etc., of different people will affect the length of time that person thinks.

In terms of efficiency, we can say that IQ causes a gap between people, specifically, it should include concentration, mental agility, spatial imagination, logical reasoning, short-term memory, and so on.

3.Persistence: Attachment is well understood. It's how long you're willing to focus when you're in trouble.

Persistence is based on self-confidence. Many of those who feel that they are not good at mathematics are not lacking in thinking skills, but that they are not confident enough for various reasons, which makes it difficult to be willing to calm down and think about a problem for a long time. When you try a method and find that it doesn't work, or when you find that you encounter difficulties in the middle, you think you can't do it and give up, which leads to a vicious circle.

I think people who are good at math generally have one characteristic, that is, they are smart. I know a lot of people who are good at math and don't take it seriously in class, and they don't do a lot of questions after class, such as my high school tablemate, he usually sleeps and watches movies in class, although other subjects are not good, but math has always been his strength. I am also very grateful to him, his help made my math much better.

I don't know if you can set unknowns for this question, so I provide two algorithms:

The first type: from the question, it can be seen that the train takes 50 seconds to pass 1140m and 80 seconds to pass 1980m, so the time to pass 1980-1140=840m is: 80-50=30 seconds, that is, the speed is: 840 30 = 28m seconds.

The algorithm of the body length: 28*50-1140=260m, so the result is: the body length is 260m, and the speed is 28m secondsSecond: the train length is x and the speed is y

1140+x=50*y

1980+x=80*y

Solution: x=260

y=28 speed is 28 meters seconds Length: 260 meters.

Set, the body length x meters, then the distance traveled across the bridge is: (1140 ten x) meters, the speed is (1140 ten x) 50 the distance traveled through the tunnel (1980 ten x) meters, the speed is (1980 ten x) 80 equations [the equivalent relation is speed]:

1140 x ) 50 = (1980 x x) 80 solution x = 260

1140 x ) 50 = 28

The length of the car is 260 meters, and the speed is 28 (meters and seconds).

Solution: Let the train speed be x meters and seconds. The body is y meters long.

50x=1140+y①

80x=1980+y②

Get. 30x=840

x=28 substitution , get.

y=50*28-1140=260

The train length is x and the speed is y

1140+x=50*y

1980+x=80*y

Solution: x=260

y=28 speed is 28 meters seconds Length: 260 meters.

The time ratio between the two times is 50:80, which is 5:8

Because the speed is the same, the distance ratio is also 5:8

Then 8-5=3 gives how much longer the tunnel is than the bridge.

And because 1980-1140 = 840 meters, the tunnel is 840 meters longer than the bridge, so 3 parts are equivalent to 840 meters, 1 part is 280 meters, and 5 parts are 1400 meters, so the length of the bridge plus the train is 1400 meters.

Train length = 1400-1140 = 260 meters.

The train speed is 1400 50 = 28 m sec.

The length of the car is L, and the speed is V

50v=1140+l

80v=1980+l

Finally, l = 260, v = 28

The body length is x meters.

1140+x) 50=(1980+x) 80 solution x=260

Speed (1140+260) 50=28 m/s.

Let the train have a speed of x m s and a body length of y m

2y+1140）/x=50 (2y+1980)/x=80

That is, 2y+1140=50x

2y+1980=80x

Subtract the two formulas to get 840 = 30x

So x=28

Bring in 2y+1140=50x.

y=130

Let the length of the train be x and the speed of the train be y

1140+x＝50y

1980+x＝80y

50y-1140＝80y-1980

30y＝840

Speed: y 28 m/s.

Vehicle length: x 260 meters.

1)2/3=24/36

So 2 3>12 19>4 7>6 11>8 152)1 2=120 240

So 8 15>1 2>6 13>5 12>4 113)13 10>14 11>5 4>16 13>17 144)3 5>4 7>5 9>6 11>7 135)2 7>5 18>4 15>1 4>2 9 All upside down.