a, cho a,b,c là các số dương thỏa mãn a^3/b+b^3/c+c^3/a=ab+ac+bc Tình giá trị của biểu thức M=(a+b+c).(1/2014a+1/2014b+1/2014c)

Cho` triangle ABC`. Trên cạnh `BC` lấy điểm `I` sao cho `BI=1/3 BC`. Chứng minh: `vec{BI}=-1/2 (vec{AI}-vec{CA})`

tính chính xác 20072008 × 20202021

Thực hiện phép tính sau: 1+2-3-4+5+6-7-8+9+...+2018-2019-2020+2021

tìm giá trị biểu thức giải kĩ giúp em!

Exercise 2: Put the verbs in bracket into the past simple or the present perfect 1. I ______ (not/play) tennis since I was at school but I _____ (be) very good at it back then. 2. A: ______ you ________ (choose) a dress for the party yet? B: Yes, I ______ (buy) one yesterday. 3. I think our teacher ______ (forget) about the test! He ___________ (not/ say) anything about it in the last season! 4. A: ____________ (you/ sell) your house yet? B: Yes, some people _______ (see) it last month and ________ (buy) it. 5. They __________ (lose) their cat. It ___________ (run) away last week. 6. __________ Helen ever __________ (try) sushi? 7. __________ you __________ (go) to the wedding last night? 8. I __________ never __________ (be) to Paris 9. This year I __________ (travel) to Athens 3 times so far. 10. Paul and Judith __________ (be) married since 1998. 11. __________ you __________ (finish) your homework yet? 12. Last night aunt Betty __________ (come) by. She __________ (tell) us that this summer they are going to Hawaii. 13. I __________ (visit) many different countries so far. Last summer I __________ (go) to Italy and 3 years ago I __________ (be) in Spain. I __________ (not/ visit) Germany yet. 14. When __________ you __________ (come) to Greece? 15. I __________ (come) in 2007. 16. __________ you __________ (watch) the film E.T. yesterday? 17. They __________ already __________ (leave) the train station 18. How long __________ you __________ (know) Jonathan? 19. I __________ (meet) him in 2009, so I __________ (know) him for 3 years 20. What __________ (happen) to Lucy last night? 21. __________ you __________ (read) “Harry Potter” when you were on holidays?

Ex1 Choose the word whose underlined part is pronounced differently. 1. A. suffered B. entertained C. polluted D. unemployed 2. A. sights B. problems C. souvenirs D. exhibition 3. A. around B.sound C. about D. country 4. A. question B. attraction C. education D. tradition 5. A. advice B. decision C. delighted D. helpline 6.A. embarrass B. missing C. classmate D. pressure 7. A. adolescence B. emergency C. helpline D. tense 8.A. delighted B. depressed C. embarrassed D. stressed

30. Young people want to go to the city to study, they____________better education. A. expectation B. expectable C. expectably D. expect 31. At first, Na felt hard to live in Ha Noi, then she was given______________,she feels better now. A, a head B. a love C. a hand D. a look 32.I’ll take you to the market later, if you like? - “________________” A. Wonderful B. You’re welcome C. Yes, I like it D. Not at all 34. Shall we rebuild some buildings in this city next year?- “________________” A, No, we can’t B.You’are welcome C. All right D. You needn’t do that 35.She told her mother that _____ a very high score in her test. A. she had got B. she had get C. she has getD. she has got

Giúp mình với ạ, mình cần gấp!!!

22: “Mom, I’ve got the first rank in class this semester!” “ ” A. Well done! B. Thank you! C. Never mind! D. Let’s go! 23. Ho Chi Minh city is the ________________ city in our country. A. biggest B.bigger C. big D. bigest 24. Nowadays many people move to urban areas to________________job. A.go on B.put down C. look for D. get on 25. Our city is getting______________polluted than whenever. A. many more B. by farmost C. much most D. much more 26. Ha Noi offeredMinh great opportunities last year, he attempted to_______________modern life. A. look for B. keep up with C. find out D. pick up 27.. If you live in a city, you will see many people and hear the noise of______________ A. traffic B.soil C. light D. air 28. People think that life in rural areas is more______________than life in urban ones. A. crowded B.modern C. difficult D. overpopulated 29. Residents in city live______________from people in countryside. A. differently B. easily C. difficultly D. happily