Chúc cậu học tốt nghen ^^ 

a) *Đa thức P(x) 
\(\text{ P(x)= 2x^3 - 2x + x^2 – x^3 + 3x + 2 }\)
\(\text{ P(x)= 2x^3 }-x^3+x^2+3x-2x+2\)
*Đa thức Q(x) 
\(Q\left(x\right)=3x^3-4x^2+3x-4x-4x^3+5x^2+1 \)
\(Q\left(x\right)=3x^3-4x^3+5x^2-4x^2-4x+3x+1\)
b)* Đa thức M(x) \(M\left(x\right)=\left(\text{ 2x^3 }-x^3+x^2+3x-2x+2\right)+\left(3x^3-4x^3+5x^2-4x^2+3x+1\right)\)
\(M\left(x\right)=\text{ 2x^3 }-x^3+x^2+3x-2x+2+3x^3-4x^3+5x^2-4x^2+3x+1 \)\(M\left(x\right)=\left(\text{ 2x^3 }-x^3+3x^3-4x^3\right)+\left(x^2+5x^2-4x^2\right)+\left(3x-2x+3x\right)+\left(2+1\right)\)
\(M\left(x\right)=2x^2+4x+3\)
*Đa thức N(x) 
\(N\left(x\right)=\left(\text{ 2x^3 }-x^3+x^2+3x-2x+2\right)-\left(3x^3-4x^3+5x^2-4x^2+3x+1\right)\)
\(N\left(x\right)=\text{ 2x^3 }-x^3+x^2+3x-2x+2-3x^3+4x^3-5x^2+4x^2-3x-1\)
\(N\left(x\right)=\left(2x^3-x^3-3x^3+4x^3\right)+\left(x^2-5x^2+4x^2\right)+\left(3x-2x-3x\right)+\left(2-1\right)\)
\(N\left(x\right)=2x^3-2x+1\)
c) 
2x² + 4x + 3
= 2(x² + 2x + 1) + 1
= 2(x + 1)² + 1
Ta có x² ⩾ 0 ∀ x ∈ R
→ 2(x + 1)² ⩾ 0 ∀ x ∈ R
→ 2(x + 1)² + 1 ⩾ 1 
Mà 1 > 0 → 2x² + 4x + 3 vô nghiệm hay đa thức M(x) vô nghiệm


Chúc cậu học tốt ^^

I. Choose the best answer to complete each of the following sentences  

1. Only by booking in advance _______ stay ion the room you like.

A. can you                 B. you can           C. you will                        D. you

2. I was brought _______ in the countryside by my aunt after my parents had pass

A. on / over        B. for/ on                C. on/off               D. up / away

3. Yesterday I ran into Sam at the grocery store. I had not seen him for years.

A. met by chance   B. visited   C. said goodbye to    D. made friends with

4. Is that ________ present Bill gave you at Christmas?

A. Ø           B. the                    C. a                     D. an

5. Life is not so easy for ________  unemployed.

A. the            B. a                                 C. an                                 D. ⊘

6. Look _____! The tree is going to fall.

A. over                 B. off                             C. in                     D. out

7. The pupils ______ we took to the amusement park behaved themselves very well.

A. whose           B. with whom                  C. whom                   D. which

8. Bournemouth, ________ we are going to visit, is a real paradise for the retired.

A. that          B. what                  C. which             D. in which

9. Sunday is the day_______ which we usually go fishing.

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

10. Take a map with you _________ you lose your way.

A. if                 B. in case                        C. so that                         D. so

11. Vietnam carried _______ an intensive program for its athletics, which included training in facilities, bot home an abroad.

A. for             B. at                   C. out               D. of

12. Plant and animal extinction leads ________ loss of biodiversity.

A. on           B. in                  C. into              D. to

13. Pay attention ________ all traffic signs when you are travelling in the street.

A. for           B. on                C. to                 D. from

14. Reviewers describe books _______ "hard-to-put-down", or "hard-to-pick-up-again".

A. as           B. for                  C. into                             D. in

15. Mary doesn't mind living _________ her own.

A. with           B. by                     C. on                    D. at

16. It is of great importance to create a good impression _________ your interviewer.

A. on             B. about                    C. for              D. at

17. When are you leaving ________ Hanoi?

A. toward          B. forward               C. for                               D. to

18. The children are excited ________ going to the circus.

A. for       B. about                           C. with                  D. of

19. While studying, he was financially dependent_______ his parents.

A. to                             B. of                     C. on                  D. from

II. Put each verb in bracket into a suitable tense

1. If we (have)... ......some tools, we (be)........... able to repair the car, but we haven't had any with us.

2. It's a beautiful house, and I (buy).................it if I (have)... ... ... ... the money, but I can't afford it.

3. So long as I (finish) work early tomorrow, I (come ) with you

4. If pigs (have)..............wings, they (fly)................

5. If you (heat)...............glass, it (break)..........

6. Suppose you (see)..................a ghost, what would you do?  

7. I'm so annoyed about my car accident. If only I (be)................... more careful!

8. I'd rather you (not put) ................ your coffee on the top of the book.

9. Jim is so untidy! If he (buy)... ..............some new clothes, he (not look) so bad.

10. After she (talk)................. to him, she (go)................. out for a walk.

11. I (sleep) .................. this time yesterday.

12. At 8 p.m yesterday, I .................. (lie)on the beach.   

13. The car is so wet. - I (wash).................. it.

14. It's time you (go) ................. to bed.

15. By the end of this year, I (work) ... . . . . . . . . ..... here for 10 years.

16.when I (enter) .................. the room, they (dance)................. together.

17.Before humans (travel).................. into space, animals (send) ..................to space on unmanned spaceships.

18. She (just/go) ................. out when I (come) ................. to her house last night.

19. While I (do) .............. my homework last night, my little brother (play) .................. with the toys

20. A house .................(build) before they moved there last year. 21. It looks as if you (see) ................. a ghost.

22. You are running as if you (chase) .................by a ghost.

23. She treats us as if we (be) .................her slaves.  

Giúp em với ạ, em cảm ơn nhiều lắm! 

I.Choose the word that has underlined part pronounced differently from the others
1.A
2.C
3.C
4.B
5.A

1. I'd like to have a bigger house.

⇒I wish..........................

2. I'd like them to keep quiet.  

⇒If only.............................................

3. You don't usually clean the floor after meals that's why it is so dirty.

⇒ Were...........................................................  

4. I'm sorry that I didn't do the homework last night.

⇒I wish...........................................................

5. You didn't tell me about that so I made him sad.

⇒If..........................................................................................  

6. I regret staying up late last night.

⇒If only............................................................................

7. I'm sorry that you can't join in the trip with us.

⇒I wish......................................................................................

8. The weather was very cold, so we couldn't go swimming.

⇒Had the weather..............................................................

⇒Had it.........................................

⇒If………….....................................

9. You are making too much noise.
⇒I wish.........................

10. I'd love to travel abroad when I leave school.

⇒If only........................................................ 

11. It might be a nice day tomorrow. I want to go to the beach.

⇒If......................................................

⇒Should.................................................................. 

12. You should apply for that job.  

⇒If I.....................................

13. I am not a doctor but I want to be a doctor.

⇒I wish...........................

14. I am very busy. I can't talk to you (too)

⇒...................................................................................................

15. You are too young to learn to drive. (enough)
⇒..................................

16. She was so beautiful that everyone looked at her when she entered the room (such)
⇒.................................................................................

17. This table is very heavy. He couldn't move it. (too)
⇒.......................................................................

18. People say that he is a billionaire.

⇒It is....................................
⇒He is ...............................

19. It is rumoured that he got implicated in the robbery

⇒He is...........................................................

20. People believe that she is living happily with her family. ⇒......................................................................................

21. She had just entered the room when it started raining heavily.

⇒ No sooner...........................

⇒Hardly.......................

22. She will never forgive you.  

⇒At no time.........................................

23. A bird is sing on the tree.

⇒On the tree.. ..................................................

24. Helen wrote a novel and made a cowboy film.

⇒Not only.......................................

25. My uncle didn't recognize me until I spoke.  

⇒Not until....................

26. “I am nervous now”, he said   

⇒He said that......................................................................

27. She said to me, “will you come with me to the party tonight?”  

⇒She asked.......................

28. “When are going to visit your parents?”, she asked me  

⇒She wanted to know................................................

29. “Don't move or I'll shoot”, the robber said to the bank manager  

⇒The robber threatened.................................................

30. “Congratulations. You have won the first prize!” she said to me.  

⇒She congratulated...................................

31. “stay here until tomorrow, please” She told me

⇒She asked.........................................

32. Shall we go to the beach this weekend? 

⇒Let's................................................................................................

33. She said such bad things to her mother.

⇒She.....................................................................................

34. I am surethat she didn't go out with him last night.  

⇒She can't.................................................................

35. It is possible that she went to bed late last night.

⇒She might..........................................................................  

36. Shecooked too much food. She didn't need to do so.  

⇒She needn't...……………………………………………………. 

Giúp em với ạ, em cảm ơn! 

Cho góc ABC = 65độ . lấy điểm M nằm trong góc ABC . kẻ MH vuông góc AB ( H thuộc AB ) , kẻ MK vuông góc với BC ( K thuộc BC ) . qua M kẻ một đường thẳng EF vuông góc với MH ( E thuộc BC )

a) chứng minh EF // AB . tính góc MEB ?

b) kẻ MN ( N thuộc AB ) sao cho góc NME = 65 độ . chứng minh MN // BC

c) trên tia đối của tia MK lấy điểm O sao cho MO = MK . chứng minh rằng tia MO cắt đường thẳng AB

Tính hợp lí (nếu có thể):

\(\left(\frac{1}{2^2}-1\right).\left(\frac{1}{3^2}-1\right).\left(\frac{1}{4^2}-1\right)...\left(\frac{1}{100^2}-1\right)\)


Mng ơi giúp em với ạ :(((