ta có :

\(x^4-1-\left(2x^3-2x\right)=\left(x^2-1\right)\left(x^2-2x+1\right)\)

Vậy \(x^4-1-\left(2x^3-2x\right):\left(x^2-1\right)=x^2-2x+1\)

\(A=\left(x^2-5x-4\right)^2+7\left(x^2-5x-4\right)+10\)

Đặt \(t=x^2-5x-4\).

\(A=t^2+7t+10=t^2+2t+5t+10=\left(t+2\right)\left(t+5\right)\)

\(=\left(x^2-5x-4+2\right)\left(x^2-5x-4+5\right)\)

\(=\left(x^2-5x-2\right)\left(x^2-5x+1\right)\)

ko k cho mình nha team mình có người k cho mình 3 k nên bạn ko k cho mình 3 câu trả lời 

a.(−4xy)(2xy^2–3x^2y)

=(−4xy)(2xy^2)+(−4xy)(−3x^2y)

=−8x^2y^3+12x^3y^2

nha bạn chúc bạn học tốt ạ 

a) = \(\left(-4xy\right)\left(2xy^2\right)\)\(+\left(-4xy\right)\left(-3x^2y\right)\)

    = \(-8x^2y^3\)\(+12x^3y^2\)

b) = \(\left(-5x\right)\left(3x^3\right)\)\(+\left(-5x\right)\left(7x^2\right)\)\(+\left(5x\right)\left(-x\right)\)

    = \(-15x^4-35x^3+5x^2\)

Question 1: How much/ time/ day/ you/ spend/ playing game?

\(\Rightarrow\)How much time a day do you spend on playing game?

Question 2: Nick/ just/ buy/ a CD/ Vietnamese folk songs/ and he/ think/ he/ enjoy/ listen/ to the melodies.

\(\Rightarrow\)Nick just bought a CD of Vietnamese folk songs and he thinks he’ll enjoy listening to the melodies.

Question 3: Ping/ not/ mind/ do/ a lot of/ homework/ in the evenings.

\(\Rightarrow\) Ping doesn’t mind doing a lot of homework in the evenings

Question 4: Marie/ / window shopping/ her close friend/ Saturday evenings.

\(\Rightarrow\)Marie s window shopping with her close friend on Saturday evenings.

Question 5: Why/ not/ we/ help/ our parents/ some DIY projects?

\(\Rightarrow\)Why don’t we help our parents with some DIY projects?

Question 1: How much/ time/ day/ you/ spend/ playing game?

=) How much time a day do you spend on playing game?

Question 2: Nick/ just/ buy/ a CD/ Vietnamese folk songs/ and he/ think/ he/ enjoy/ listen/ to the melodies.

=)  Nick has just bought a CD of Vietnamese folk songs and he thinks he’ll enjoy listening to the melodies.

Question 3: Ping/ not/ mind/ do/ a lot of/ homework/ in the evenings.

=) Ping doesn't mind doing a lot of homework in the evenings

Question 4: Marie/ / window shopping/ her close friend/ Saturday evenings.

=) Marie lik.es window shopping with her close friend on Sunday evenings

Question 5: Why/ not/ we/ help/ our parents/ some DIY projects?

=) Why don't we help our parents some DIY projects?

Question 1: A. adore     B. world     C. worker    D. word

Question 2: A. beach     B. peach    C. watch     D. chemistry

Question 3: A. cultural    B. communicate    C. music    D. student

Question 4: A. leisure    B. furniture    C. feature     D. nurture

Question 5: A. mind     B. fire     C. kit    D. socialize

TL:

1. A                     2. D                   3. A                 4. D                  5. C

~HT~

Với |x| = 2 khi x = 2 hoặc x = -2 

a, \(A=\left(3x+5\right)\left(2x-1\right)+\left(4x-1\right)\left(3x+2\right)\)

\(=6x^2+7x-5+12x^2+5x-2=18x^2+12x-7\)

Với x = 2 thì \(A=89\)

Với x = -2 thì \(A=41\)

b, \(B=\left(x^3-x^2y+xy^2-y^3\right)\left(x+y\right)\)

\(=x^4+x^3y-x^3y-x^2y^2+x^2y^2+xy^3-xy^3-y^4=x^4-y^4\)

Thay x = 2 ; y = -1/4 ta được : \(=16-\frac{1}{256}=\frac{4095}{256}\)

Bài 4 : 

a, \(3\left(1-4x\right)\left(x-1\right)+4\left(3x-2\right)\left(x+3\right)=-27\)

\(\Leftrightarrow3\left(x-1-4x^2+4x\right)+4\left(3x^2+7x-6\right)=-27\)

\(\Leftrightarrow-12x^2+15x-3+12x^2+28x-24=-27\)

\(\Leftrightarrow43x=0\Leftrightarrow x=0\)

b, \(\left(2x+3\right)\left(x-4\right)+\left(x-5\right)\left(x-2\right)=\left(3x-5\right)\left(x-4\right)\)

\(\Leftrightarrow2x^2-5x-12+x^2-7x+10=3x^2-17x+20\)

\(\Leftrightarrow-12x-2=-17x+20\Leftrightarrow5x=22\Leftrightarrow x=\frac{22}{5}\)

( x + 3 )( x + 4 )( x + 5 )( x + 6 ) + 1 

= [ ( x + 3 )( x + 6 ) ][ ( x + 4 )( x + 5 ) ] + 1

= ( x² + 9x + 18 )( x² + 9x + 20 ) + 1

= ( x² + 9x + 19 - 1 )( x² + 9x + 19 + 1 ) 1 

= ( x² + 9x + 19 )² - 1² + 1 = ( x² + 9x + 19 )²

x² - 2x( y + 2 ) + y² + 4y + 4

= x² - 2x( y + 2 ) + ( y + 2 )²

= ( x - y - 2 )²

II/  Give the correct form of the verbs in brackets to complete the following sentences.

1. Don’worry! I (do) it for you tomorrow.

…………………will do………………………………………………………

2. My father  (not ) watching TV.

………………doesn't …………………………………………………………

3.  My father (call) you in 5 minutes.

…………………will call………………………………………………………

4. The telephone  (ring).  Can you answer it?

………is ringing…………………………………………………………………

5.  We believe that  she (recover) from her illness soon.

…………………………will recover………………………………………………

6. The sky is getting darker and darker. It (rain).

………………………………………………is raining…………………………

7. I promise I (return) school on time.

…………………will return………………………………………………………

8. A: We've run out of milk. B: I know, I   (buy) some.

………………………………………………will buy…………………………

9.  If it rains, he (stay) at home.

………………………will stay…………………………………………………

10. You (take) me to the zoo this weekend?

………Will you take…………………………………………………………………

11. I think he (not come) back his hometown.

…………………will not come………………………………………………………

12. Mary  usually (have)  breakfast at 7.00.

……………………has……………………………………………………

1 , will do

2 , doesn't li.ke

3 , called

4 , is ringing

5 , will recover

6 , is raining

7 , will return

8 , will buy

9 , will stay

10 , Can / take

11 , won't come

12 , has

I/ Choose the word whose underlined part is pronounced differently from that of the other words

1. a. together             b. connect                 c. copy           d. opposite

2. a. table                   b. dangerous            c. skate          d. war

3. a. cinema               b. countryside          c. think          d .live

4. a. remember          b. excited                  c. help           d. exams

I/ Choose the word whose underlined part is pronounced differently from that of the other words

1. a. together             b. connect                 c. copy           d. opposite

2. a. table                   b. dangerous            c. skate          d. war

3. a. cinema               b. countryside          c. think          d .live

4. a. remember          b. excited                  c. help           d. exams

* Sai xin lỗi ạ *

@Duongg