Đại số 9 ôn thi giữa kỳ 1: Tìm x - Bài 1-3 #toan9

Today we will learn about the section on reducing radicals in the structure for the 9th-grade math final exam Take the observation channel observe sentence 1 sentence 2 sentence 3 sentence 4 sentence 5 Let's go to question 1 Then we have something like this Then these close friends of yours I will know the one who dares one fifth Multiply by the square root of 25 and 50 must be multiplied by 25 in common I can put 5 squared right x plus 5 or x plus 2 Number 5 is still number 5 if you add 2 just take it as is We managed to place 9 outside for the 9 and 18 table but 9 in my opinion is 3 squared It is 3 squared and this is x plus 2 I'll move the 9 table over there Then you set the conditions here The condition is There is an x plus 2 in this equation So we set the condition that x plus 2 equals zero x plus 2 is greater than or equal to 0 Which means x is greater than or equal to -2 Because 2 x is greater than or equal to 2 is the meaningful condition of the problem okay Then at that time the equatio The equation is now balanced Now let's move the 5 squares outside What does moving the 5 squares outside become We have this basis here If AB are both positive numbers AB are both positive numbers where A squared is inside the root Then the one taken out will be A squared B That means if there is a squared term inside the square root And the other term is also positive So we will have 5 squares Take it out and make it 5 But this number 5 combined with this 5 Then it's all over So we are just the square root of x plus 2 This one I'll leave as is I'll keep this part as it is What about this one 3 squared is taken out to become the number 3 Therefore we have is the cube root of x plus 2 By tone 9 Then this is equivalent to As you know we have an example here AB minus AC For instance adding A Then in this case we have A Common factor test sample When the test sample is placed outside it will be B minus C plus 1 So for this part I will find out tha This coil is tightened like the A number It is a common factor When you put it outside there will be one like this Because this one does not have anything we understand it as 1 So it will become 1 minus 5 Plus 3 multiplied by the square root of x plus 2 By tone 9 So we have 1 plus 3 is 4 4 minus 5 is negative 1 So this total is actually negative 1 That is the sound of x plus 2 equals negative 9 Then this case will become a precedent The square of x plus 2 will be 1 And here I will try solving x plus 2 equals 1 And x equals negative 1 Does this first condition meet the requirement I answer yes so we conclude that the condition is satisfied So the answer is x equals negative 1 X equals negative 1 This must be 9 Then what would this person be 9981-2 is 79 We are not recognized as 79 This is a similar exercise Similar exercise It's like homework okay Homework our assignment is The square root of x plus 2 over 4 Minus 2 times 4x plus 8 Minus the square root of x plus 2 Minus 5 We'll do the second exercise In the room I looked around This is definitely it 4x plus 4 is a square 4x plus 4 is exactly a square it is x minus 2 squared always zero for all x We can write it out for all x Then we have two options Option 1 is that we will use this formula The square root of a squared Will be equal to the opposite of a right The square root of a squared will be the absolute value of a Then when that This equation will become The equivalent equation The square of x is 2 The square of x is 1 The current situatio The opposite of x is 2 equals 7x is 1 As you know when we meet we will make a decision By means of x 2 Then I knew that the opposite of a would be what X is only 2 equals 0 If a is a large number equal to 0 x is 2 times a If a is a negative number Then we will handle the issue like this If x is greater than 1 by 2 I can solve this problem first X is only 2 greater than 0 Equivalent x equals 2 This value is only for this case If x is greater than or equal to 2 Then x is 2 it is x is 2 and you on the right side of me goes down here by 7x the letter 1 en this person would be equivalent to We will return that is here we have such experience here there is 7x here there is x If you're older you're 7 times older right so I'll move x to this side Here's the X shape there's this number 1 here I'll switch to this side add 1 please this will become I'll write the x first 7x x's With one word two return to change the mark 6 times the sound 1 equals and we reduce x by the letter 1 sixth because our condition is no condition at all For all x therefore we take this fruit as karma a second case we need to look at what is it the X shape 2 yes large is 0 we have already considered it is less than 0 right x is negative 2 we consider the case where it is less than 0 which is equivalent to x being 2 then what does this number 1 become a equivale If the value of x is 0 then its opposite is equal to x just like the opposite of a is equal to a if a is 0 What will this person become Its current state is The current state of ngoc x chừ 2 by 7x from 1 It is equivalent to here I will reveal the jade When revealing the jade this is now x otal 2 equals 7x minus 1 It is equivalent to what I just said experience is If you put it First move you 7x over here or move you x over here Then the experienced person will be moved to this side because this side is bigger but when they are moved she still knows x before It means in this case it will be 8x This number 1 If I move to this one it becomes plus 1 right So it becomes 3 right So we will have 2 fractions That is now 6 Now 1 out of 6 and 3 out of 8 Dear this is how to handle the first issue That is we use fake goods What is the second way to resolve the issue This is how it's done We will look at the second way We consider the issue as a period We consider it as a period If you meet a certain room The room of fx By removing x Do you remember this What does this correspond to Like the structure it's equivalent First is g Must be greater than or equal to zero You still remember that This room is very clean Its nature is zero-sized You this one wants to play with this one Want to be the same size as this one Then you also have to be zero-sized Right Just like you do I want to enter the mainstream society so I have to Personal achievements I must value and achieve the standards of The people of the ruling society Then This house is already as big as nothing So this thing must be as big as nothing What if the g is not big How would you do it How can it compare to this house It would be worthless First we must have a large g equal to zero Then we have an action that is These two people now Are all equal to zero Then we average both sides up If you average this side up you lose the balance That is it becomes fx It is the general solution Then it is the general solution Then this is the structure of this equation solution Then what would our equation be equivalent to This one looks at Then this person plays the role of gx Then this person plays the role of fx So we think as before That is 7x-1 must be greater than or equal to zero 7x - 1 is not equal to zero Therefore 7x - 1 must be greater than zero That is the condition for us to talk We have We have 7x-1 What should we do in this case There are two options: one is for you to separate yourself and do each thing individually the other is to persist with your own determination Then it's okay to just write normally here It's okay to just write normally Then this is x Because x will be equal to 1 right We have a movement that changes the sign That is here it is direction 1 When we move here it becomes post 1 Switch the sign only The second is for these people 4 x 4 pile in the afternoo By 49 x squared 2 times 7 times 1 is 14 Pile 1 X is greater than equal My rule is to change with sign change Here when multiplying I move it to the other side and when dividing it becomes division Therefore x is equal to 1 over 7 Then here we are we have We will move to another part Then these are x squared This one is 49 x squared Then the number 49 is larger So first you are larger so you stay And the smaller one moves to the left Then we agree to move to the left Sing with the right Move to the left with the right But when I move whoever joins me they join me Then this is 49 this is 1 But if we elect the 1 here that's 48 right Then I'll write 48 here Come here at 4 o'clock this afternoon Is that right Adding 4 makes it 2 PM Adding 4 becomes 10 AM So it becomes 10 AM Continue 4 to here Become 4th dimension What is 1 dimension 4 Approximately 3 percent How many did I just test 3 parts of 1/6 and 3 parts of 1/8 right So now regarding skills the accuracy of personnel you still remember for the department that A x normal B x plus C By 0 We factorize the number Can the machine be stopped to give the correct answer Second We use another force which is Multiply A by C Take the first coefficient multiplied by this last one Then reverse the process The numerator Is m n But in that case you By b Then we will separate this b M n is the correct shape right So here we can write like this That is 48 multiplied by 3 We can split the image into 48 parts Then can I make it into 2 this time Is it 24 3 Is it 8 right 3 Then Can anyone make 10 Is 48 equal to 6 times 48 Does anyone have a 3 x 8 x 24 that shows a result of 10 Is 8 x 18 correct This 8 x 18 Is 18 x 8 the same right Then the difference between these two is equal Because here is the minus sign So I put this as minus like this Then minus 18 Plus 8 x is 10 So it is I will analyze it like this 48 times square minus 18 times plus 8 times minus 3 equals 0 Duyang is equal to X multiplied by 1/7 And we will have 8 x subtract 3 times the opposite Did you guys manage to get 6 x outside right 6 times 1 equals 0 And so this will be equivalent to having 2 tasks: one is x equals 3 equals 8 This one is one seventh the size So take it A second task is x equals Minus one six X minus one sixth Then this one is out Because it does not meet this condition So our numbers are just this one task The place where you deduct one sixth This deduction of one sixth please The one sixth deduction must be The direction according to this condition where x is equal to 2 I don't indulge in it Then this one is out Out X is equal to 2 minus one six Okay see you later That's it With this second exercise But we have two ways to do it We have two ways to do it One approach is related to the total amount of food Then bring it to the point of opposition Then this method one But But there are some that don't have a clear meaning so I 'll break them down Here is the value of the pair That is there is a clear pair to break out But there are some pairs that have no value Then it is necessary to do it the second way If you can't do it the first way Method 1 will not work For example Article 3 goes here This is lesson 3 Then clearly this one is inside It's not necessarily food So then we don't have to do it the first way But we will have to Do it the second way That is the form of the second way Then this is exactly my type right It really is my type This is exactly the type Then how do we handle the issue Then we handle it like this Project Equivalent Equivalent project 2 items Item 1 is Gx which is the one you 2.7 Larger than 0 Second item X normal Minus 8x 16 By 2x 7 ordinary Have you used it yet Now the game uses the best bow unloading technique We go step by step one step at a time What does this equate to If the event is 2x 7 equal to 0 we don't have to change the sign then nothing will be gained X is equal to minus 7.2 Change the sig This player uses the straight food to remove the bow The game will detect a thing that This player has 4x normal right This one is a regular one This one has a regular one Then when you say you transfer the normal x here it will only be 3x normal Game should be done step by step step by step This side is turn it off a bit to make it neat Like we will do it step by step Continue There will be 2 x 2x here It will be 28 28x But here I move the 8 to here Then it becomes plus 8x 28 plus 8 28 plus 8 is 36 So we will have plus 36x Here 7 times is 49 I move 16 over Then it becomes minus 16 What is 49 minus 16 33 Is 33 correct Add 33 By 0 Here we observe the numbers 3 36 and 33 Then First I can divide it by 3 because it is divisible by 3 Remember that we have had such experiences before If a x is normal Plus b x plus c Equal to 0 Then a plus b plus c equals 0 Equal to 0 Then there is 1 solution That is 1 okay There is one root which is 1 The other root is Equal to c over a That is the person who built the project People tried to bring these digital generations If it is zero Then there is one root equal to 1 What about the minus sign If it's a minus sign here then here it becomes a minus sign Then this place will become minus 1 That's it So here you observe and found out something is 1 minus 12 Plus 11 Equals 0 right So there is one solution There is one solution which is minus one And when there is a root of 1 then there is a factor of x minus 1 This is one way of thinking But there is another way of thinking and we still try it more than the idea That is we will analyze it like this I take this 1 and multiply it by 11 1 multiplied by 11 But that equals 11 right But this 11 is different One plus eleven is twelve right Right It's exactly twelve so that's the idea The twelfth item is separated Then let's make it stylish X large when equal to 7 and a half X squared plus x plus 11 x Eleven plus zero equals eleven And thus we will obtain 1 factor which is It goes outside Then it will have x plus 1 So it will have x plus 1 as a common factor And Then we will get two solutions The first test is X equals negative 1 But is this negative 1 strong enough to be greater than negative 7 halves Minus 1 is greater than minus 7 halves Is it larger than exactly What about x minus 11 What about minus 7 and a half Smaller right Therefore this type So we only have one solution That is x equals negative one This is the first tone Then we don't have to pay the conditions because this one is not a condition Map number X is pronounced as 1