Đáp án: `C_{min}=15⇔x=\frac{5}{2}`
Giải thích các bước giải:
Sửa lại: `C=4x+3+\frac{1}{x-2}(x>2)`
Áp dụng BĐT Cauchy ta có:
`C=(4x-8+\frac{1}{x-2})+11≥2\sqrt{(4x-8).\frac{1}{x-2}}+11=15`
Dấu bằng xảy ra `⇔4x-8=\frac{1}{x-2}⇔x=\frac{5}{2}(tm)`
`C=4x+3+1/(x-2)`
`⇔C=4x-8+11+1/(x-2)`
`⇔C≥2\sqrt(4(x-2)+1/(x-2))+11`
`⇔C≥2+√4 +11`
`⇔C≥2+13=15`
`''=''`xẩy ra khi :`x=2,5`
1. He has been at home since he (buy) a new smart phone
You ask Lisa questions about herself and her family. Write the questions. - You know that Lisa reads a newspaper every day. You want to know which one. Ask her. -> _________________________________________?
II. Use the words in the box to fill the text below: (1pts) comedies national viewers interesting 7 o’clock news on VTV1 is a _____________(1) television channel in Viet Nam. It attracts millions of ____________(2) because it offers many different ________________(3) programmes. The______________( 4) tells people what is happening in Viet Nam and the rest of the world.__________(5) bring a lot of laughter and help people relax after a hard working day.
Tìm số lẻ có 4 CS biết tổng các CS bằng 26, tích các CS là số tròn chục và giá trị của số đó ko thay đổi khi đổi chỗ CS hàng nghìn cho CS hàng chục, CS hàng trăm cho CS hàng đơn vị.
ai giúp e 2 câu này với:(( , trừ 1 nhỏ bài 2 ra
Exercise 1. PHRASAL VERBS with 'COME' come across come forward come in for come into come out come to come up come up with 1. Sorry, I can´t meet you for dinner this evening. Something __________ at the office.2. When her grandfather died, Hannah __________ a vast fortune.3. The boss wants us to __________ ways to improve our company´s image.4. The bill at the restaurant last night __________ $125.5. When does the new Kevin Spacey film __________ ?6. Tracey and Oscar __________ a charming little village as they were driving down the coast.7. The government has __________ severe criticism over its handling of the hostage crisis.8. The police are asking anyone who has information about the robbery to __________
Please !!!! help me I need it urgently CHIA THÌ TIẾNG ANH - Lớp 5 1. Every morning, Linda (get)………......up at 6. She (have) …………… Breakfast at 6:10. After breakfast, she (brush) …………..her teeth. She (go) ……………..to school at 6:30. She (have) ……………lunch at 11:30 at school. 2. We (watch) …………….T.V every morning. 3. I (do) ……………………my homework every afternoon. 4. Mai and Lan (play) ………………….games after school. 5. Vy (listen) ………………to music every night. 6. Where (be) ………………..your father now? He (read) ………………..a newspaper. 7. What ………….you (do) ………………? I (be) ……….a student. 8. Where ………….you (go) ……………….now? I (go) ………………to the market. 9. She is cooking and we (do) ……………………..the housework. 10. He isn’t in the room. He (play) ………………..in the garden. 11. Look! The birds (fly) …………………………. 12. I (go) ………………….to school by bus every day, but today I (go) ………………………..to school by bike. 13. Listen! Mai (sing) …………………………. 14. They (play) ………………………volleyball every afternoon. They (play) ……………………volleyball now. 15. Mai (brush) …………………..her teeth every morning. She (brush) ……………………her teeth now. 16. Listen! Lan (play) ……………………….the piano. 17. Mai (be) ………………….tired now. 18. It is 6:00 p.m. Mary is at home. She (have) ………………….. dinner with her family around six o` clock. 19. Where is your father? He is upstair. He (watch) ………………T.V He always (watch) ………………………..T.V at night. 20. Our teacher (live) ……………………..on Quang Trung street. 21. §ao and Mai (do) ………………………the housework now. 22. What ………………your mother (do) ……………….? She is cooking. 23. How …………………you (go) ……………to school every day? 24. Nam (go) ………………..to work by car every day but today he (take) ………………………a bus. 25. Where ………………..your father (work) ……………..? In the hospital. 26. Look! The teacher (come) ……………………… 27. She is very clever. She (speak) ………………….4 languagues. 28. Steve (smoke) ………………….10 cigarettes a day. 29. We usually (have) ……………………dinner at 7: 00 30. Anne (wash) ………………….her hair twice a week.
vẽ anime bằng ap ibispaint cho mik đc ko ạ đẹp nha
Turn into passive sentence: Which car will Mary buy?
I. Read the following passage and answer the questions ( 2 ps) Australia is a island continent in the South Pacific. The capital is Canberra, but the city with the biggest population is Sydney, which has nearly four million. English is the first language of most people, but there are also immigrants who speak other languages. *Questions: 1. Where is Australia? => ................................................................................................................... 2. Is Canberra the capital of Australia? =>.................................................................................................................... 3. What is the population of Sydney? =>.................................................................................................................... . 4. Do Australian people only speak English? => …………………………………………………………………………........
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