Seminar - Hệ phương trình: kỹ năng chính và cách ra đề ( thầy: Nguyễn Hữu Hạnh )

What is the difference between the first and the second method? The first method is to combine the two methods. This method is not too simple for all students. But if a very ordinary student has the ability to combine the two methods together, then the second method is a very basic method. The first method is to combine the two methods together. The second method is to combine the two methods together. There are a lot of examples like this. So where do you get the time to prepare for this subject? Because I have a problem. When I was a student, I had time to teach only a few lessons. Of course, the time I spent preparing was enough. But when I went to school, I did not have much time to prepare for the lessons. But the teacher who taught me did not give me a lot of time. He only taught me the basics. And he gave me a path to create those lessons. So I will remember it. Not only do I remember it, I also use it to share with others. So what I want to share with you is that I want to share with you how to create those lessons. And I want to share with you how to create those lessons. So what do you need to do to create those lessons? So I did a test on this side. Now I will show you how to do it. This is a square. Add together 3x3x4. It's too easy for a first grade student. A second grade student can do it. But a first grade student is a second grader. So this is 9x18. So people are set up a program. After the program is completed, they go back to the classroom. So what do I do now? What do I want to do? What program do I want to give you? It's simple. I just need to add 2x2 to make it easier. So I use this to help students who are just starting out. So now I choose. Now I choose x square. Add 2y. Add y square. Add 7. And I add 6x8. Actually, I don't care. Because I have chosen x square 4x2. So the number on this side will only depend on this side. So now I will choose this side. If you know how to do it. For example, add 3y. Add 3y. So I will have 3y. And I add this. And here is the equation. So I have to add 2y here. Here. I have to add x here. So I have to add 2y here. I have to add 2y here. So I have to add x here. I will have to add y. This is the equation. So I have to add 2y here. In short, when we combine these two, and create a formula, it is very likely that we will succeed. It is very likely that we will succeed. So now I want to do... If I add 2y, It's like 2-1-9-2. At that time, the decider is at the last row. That's what I'm saying. The key is that this statement has to be free. just word This can be exposed. you can define this statement is a-v You can define this statement is a-v you can be apart something another something If there is a 2B, we just need to calculate the 2 here. For example, The square root of 4pi We multiply by the square root of 4pi This place must be minus 2pi So we subtract 3pi So we subtract 4i We subtract x So we get 3x plus 4x We multiply by y But there is a blank space below So it will look like this So we subtract 4i Subtract 3pi Subtract x and multiply by y Does anyone know the answer? x is 1, y is 2, y is how many? xi 4 is 2 y is 2, y is 4, y is 2, y is 6 If we solve this problem What is my theory? Because I have the experience that The problem can be simplified Simplified by combining We will do it again But it needs to be simplified Because we have to combine But there must be a goal to combine If we just play together It is not deep enough That's it Like this I invite Mr. Kho to give me a piece of paper And write it here Can you feel it? You can feel it We start from a simple equation We can choose X to be equal to 1, Y to be equal to 1, etc Then I divide it into two elements One element is the equation of the upper equation The other element is the equation of the lower equation If we want to make the problem simple Just add two together It will be a rule If we want to make it more complicated We can subtract i sub b A times B, or A plus 2B, or A times 2B. All of the ideas are usually based on that. It's not like there's a 2 above and a 3 below, or a plus a minus a minus a. It's not like that. But the ideas are already there. The ideas create the equation. Because it turns out that there are only two ideas in a set of equations. There are only two ideas. The problem is that for each set of equations, we will have a set of equations like this. Four sets of equations. The set of equations is very simple. It's all about the second equation, not the second equation. So how do we combine these two equations together to create the equation? If we look at this equation, this is a square. If we look at the top, the top is a square. And this one. This is the second equation. We only care about the second equation. So if we multiply by 3, multiply by 3 here, we get 2B. And that's the equation. So this equation will be 1 plus 13. So we get 1 plus 13, which is the second equation. And for this equation, we don't care about the first equation and we don't care about the second equation. We only care about the second equation. But if we want to create an equation, if we look at the number of i's, here is 2, we can't create an equation that is opposite to 2 here. So 2 is equal to 4. 4. Here is 2. 4 is equal to 4. So 4 is equal to 4. And 2i is equal to 12i, which is 12. So this is the second equation. And the second equation, we get 1 plus 12. We get 1 plus 12, which is the second equation. And this is the third equation. So these equations, if you give them to students, they will be very different. They will not be able to solve them. Some of you even want to do math to figure out how to solve them. Because in the word 2, there is a very deep line. So the word, I don't know exactly what the word is. This word is a tree. But there is another word. That is, there is another tree. It is the word 5, which is the word forest. That is, if it is only 1, it is only 1. But if there are 2 trees here, it is the word forest. We have 10 trees here. So that means when these two equations are together, if someone is very good at it, he can handle it, if not, we have to combine them together. And how to combine them, how to solve them, depends on if there is a common purpose. That is, we create a formula. If there is a purpose and a formula, we can solve it successfully. I will show you another equation. But this equation is a different equation. For example, as we know, there used to be a formula like this. x plus y plus 1 times x plus 2y plus 3. For example like this. In other words, we have derived a long equation. Then we multiply it here. So when we multiply it, there are two ways to multiply that we know but we don't need to combine. Oh, I see. So it is the equation plus 3y plus 2y. I have this experience. In other words, we multiply and take the second element, the first element, multiply the first element and it will be the second element. But it only has x and y, it is the same. So this x plus y and this x plus 2y are very similar to x plus 2 multiplied by x plus 1 multiplied by x plus 2. The formula is the same. So it will be x plus 3 plus 2. Then it will be x plus 2 times x plus 2. Then it will come to the first element. I don't take this one and multiply it with this one but this x plus y multiply it by 3 and it is 3. 3 times x plus y. Then it will come to the first element, multiply it by 1 and it is x plus 2. So it will become 4. Yes. You do it. My idea is that I want to choose the left element. Yes, you do it. Yes. So people will think like this. Now I have created two two projects and after connecting them I will get this project. And when I get this project, I don't have enough experience. Sometimes I have a lot of questions and then I move to another place. So So now now I can say that A is the left element. For example, I want to say that this is the left element. Yes. So now I will separate them into two. Yes. One is left and one is right. Yes. So now the problem is that I choose A because this is the left element. Yes. The left element is B. So this is the left element of A. This is the left element of Y. So this is the left element of Y. So now the problem is that I just create No. Two elements above here. Two elements below are Y elements. Five elements above are Y element. Nine elements below are Y elements. If I put this into a box, this is already ten. This is the left element of Y. So I just put a little bit of experience in here, one or two, one is one, one is two. Yes. Because we don't know how to eat For example, like this Put it in the rice cooker It will be cooked So when we create this project So how do we know what to do? Because if we start thinking about how to create food We may not be able to create food How do we know that now we have enough Just now the family is eating But naturally we will add If we don't know what to add, let's try adding So it can be 3x square xy axis plus 2x square minus 4x plus 5y equal to 5 4 times 5 is equal to 0 So this is a choice But we already know that this choice is not a successful choice And if we subtract This is 1 plus 1 Plus 1 minus 1 will be like this 1 minus 1 will be like this It will be like this So how do we know that this is a success? Ah, like this It will have experience To know that A is square plus yy plus c is square plus a is plus yy plus c is square When we have a solution like this Then we pay attention to the property of y The property of y If y is not equal to y Then what is the chance? And if y is not equal to y Is not Not equal or not Then it will not be equal to y It has such a symbol So when we have a solution like this We just don't need to know the next part We just need to know this formula We just need to know that this is not equal to y So this is not a success So the formula is not a success But if 1 minus 1 When we know this Then we know that A is a very high success And this is the most difficult thing to solve So now let's go back to the problem of nature This problem So let's try Now in the problem of nature We try to solve a formula So we just take the equation Minus Minus 2y Minus what? Minus 2y So this is the problem There is a door Because many other factors can also be found 1 minus 1 The square root of 2y That's all So what is this? Is it possible to solve it? Minus 2y Because this is the derivative It is It is x Minus x plus 12y So now we use it like this So it will be Here Minus 5y Minus 4y Minus 6 For this problem We have a solution A solution That is We solve this equation Then we perform this equation According to the equation of V Equation of V And that's it Then the equation will appear If you can solve it If you can't solve it, you can't do it That is, if you can't solve it, you can do it If you can't solve it, you can do it You will know right away Can't solve So do Now for me I will perform this Through these two factors That's simple Because there is a simple equation This equation is very simple Here we want to have 2y So this is where it has to be That is, the function of the equation It is the function of this equation This equation will be Here we need 2, right? So we need 7 Minus 2y plus 2y And minus 6 That is, plus 6 and 0 So we have a model U times V Minus 3U Minus 2V Plus 6 and 0 Do you know how to solve it? It will be U minus 2 Minus V minus 6 And that's it So when we Uh It must be these two equations The equation is like this So it's not always that we don't succeed It's not always that we don't succeed So Uh Some students have written That is, let's say these two equations Prepare for each other to succeed Minus V Minus 6 and 0 So for V and U There is no other way To know if it will succeed or not So we just have to wait a while And the equation will be