1. \(4x^2-9y^2=\left(2x\right)^2-\left(3y\right)^2=\left(2x-3y\right)\left(2x+3y\right)\)  

2. \(x^2-\left(2y\right)^2=\left(x-2y\right)\left(x+2y\right)\)  

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

4.  \(8+x^3=2^3+x^3=2^3+3.2^2.x+3.2.x^2+x^3\) 

                                   \(=8+12x+6x^2+x^3\)  

5. \(8x^3+27=\left(2x\right)^3+3^3\)  

                    \(=\left(2x\right)^3+3.\left(2x\right)^2.3+3.2x.3^2+3^3\)  

                    \(=8x^3+36x^2+54x+27\)  

6. \(\left(a+b+c\right)^2=a^2+b^2+c^2+2ab+2bc+2ac\) 

7. \(\left(a-b+c\right)^2=a^2+b^2+c^2-2ab-2bc+2ac\) 

8. \(\left(a-b-c\right)^2=a^2+b^2+c^2-2ab-2ac+2bc\) 

Tìm nghiệm của đa thức sau:

G(x)=x3-5x+3

Ta có: 3x-5x+3=0

           3x-5x    =0-3

            3x-5x    =-3

              -2x      =-3

                  x      = \(\frac{-3}{-2}\)  

                  x     = \(\frac{3}{2}\)

1. i like the saying : ' .................. is better than cure ' 

a. prevent                           b. preventing                       c. prevention               d. prevents

2. if someone has got ................ temperature  , they feel very hot

a. the             b. a                         c.an                       d. không điền

3. we shouldn't cross the street outside the............

a. pavement                b. footpath          c. sidewalk              d. zebra crossing

4. mr . thanh has ............ appointmemt at four o'clock ....... this afternoon

a. an, a           b. a, an          c. an, an             d. an , không

5. when i saw her, she looked ............

a. happy        b. happily            c. to be happy                   d. being happy 

6.A: " thank you so much for your help "  B: ................

A.no problem             b. it's my pleasure           c. don't mention it                 d. best wishes

1. they dancing tonight are going ?

=> Are they going dancing tonight?

2. are't sunglasses why your you wearing ?

=> Why aren't you wearing your sunglasses?

3.is university studying at Mary what ?

=> What is Mary studying at university?

4. you why breakfast have don't ?

=> Why don't you have breakfast?

5. buying many are potatoes you how ? 

=> How many potatoes are you buying?

6. you your with mother help housework the do ?

=> Do you help your mother with the housework?

7. your mine modern house is than more ? 

=> Is your house more modern than mine?

8. she from till does work hard night morning?

=> Does she work hard from morning till night?

1. A. used to          B. use to          C. be used to          D. use

2. A. is          B. are          C. were          D. was

3. A. had to          B. have to          C. has to          D. must have

4. A. was         B. had          C. has          D. is

5. A. will come          B. comes          C. was coming          D. come

6. A. hasn't come          B. didn't come          C. haven't come          D. came

7. A. doesn't          B. don't          C. won't          D. didn't

8. A. were          B. is          A. are          D. was

9. A. yesterday          B. this day        C. those days        D. tomorrow

10. A. because          B. since          C. as          D. even though

1. I usually stayed up late to watch football matches last year.

=> I used to stay up late to watch football matches last year.

2. There were some trees in the field.

=> There used to be some trees in the field.

3. She doesn't live with her parents anymore

=> She used to live with her parents more than now.

4. He is not a poor man anymore.

=> He used to be a rich man.

5. They didn't often go to the cinema every Sunday last year.

=> They didn't use to go to the cinama every Sunday last year.

6. My hair now is much longer than that in the past.

=> In the past my hair used to be shorter.

7. I don't have time to collect stamps as when I was in primary school.

=> I used to have much time to collect stamps when I was in primary school.

1. A. same          B. traditional          C. magical          D. normal

2. A. excited          B. upset          C. interested          D. able

3. A. temple          B. festival          C. river          D. peace

4. A. escape          B. precaution          C. talk          D. appearance

5. A. Novel          B. Fiction          C. Picture          D. Legend

6. A. match          B. fit          C. go with          D. measure

7. A. at night          B. in the night          C. at every night          D. in every night

8. A. at          B. from          C. in          D. on

9. A. in          B. on          C. at          D. after

10. A. at          B. before          C. between          D. after

11. A. in          B. at          C. during          D. on

12. A. either          B. so          C. too          D. either

13. A. in          B. at          C. on         D. \(\varnothing\)

14. A. after          B. before          C. between          D. after

15. A. Why          B. How much          C. how          D. What

16. A. look          B. lost          C. lose          D. find

17. A. spent          B. came          C. left          D. went

1. The student isn't. in class at present.

2.She always washes the dishes after meals.

3. What does your father usually do in the evenings?

         He usually watches TV . He isn't watching TV at present.

4. Nam didn't visit the museum with his class last sunday because he caught a cold.

5. Boys like playing. marbles or catch while girls enjoy skipping rope or chatting.

6. Keep silent, please. Our teacher is explaining the lesson.