Đáp án:
Giải thích các bước giải:
$x^4 - 4x^3 + 12x - 9 = 0$
$⇔ x^4 - x^3 - 3x^3 + 3x^2 - 3x^2 + 3x + 9x - 9 = 0$
$⇔ x^3(x-1) - 3x^2(x-1) - 3x(x-1) + 9(x-1) = 0$
$⇔ (x-1).(x^3+3x^2-3x+9) = 0$
$⇔ (x-1)(x-3)(x-√3)(x+√3) = 0$
$⇔ x = { 1;3;√3;-√3 }$
x^4 - 4x^3 + 12x - 9 = 0
<=> x^4 - x^3 - 3x^3 + 3x^2 - 3x^2 + 3x + 9x - 9 = 0
<=> x^3(x-1) - 3x^2(x-1) - 3x(x-1) + 9(x-1) = 0
<=> (x-1).(x^3+3x^2-3x+9) = 0
<=> (x-1)(x-3)(x-√3)(x+√3) = 0
<=> x = { 1;3;√3;-√3 }
Vậy....
giải thích vì sao sản xuất công nghiệp lại có tính tập trung cao độ Hãy cho biết các thế mạnh để phát triển công nghiệp thực phẩm ở Việt Nam
IV. Each sentence has ONE mistake. Find and correct it. 1. Huong spent half an hour to tidy the bathroom. 2. Peter isn’t used to eat with chopsticks when he lives in Viet Nam. 3. I don’t know where my pen is. I’ve looked at it everywhere. 4. We last saw a cowboy movie since we were in the city. 5. The man sang English songs beautifully is my elder brother. 6. Five dollars are too much for this cake. 7. The story wasn’t short enough for me to read it in one day. 8. She finds it interestingly to do the housework. 9. I would rather you not go to school by motorbike. 10. These people are working very hardly on the farm. Your answer: Mistakes Correction Mistakes Correction 1. 6. 2. 7. 3. 8. 4. 9. 5. 10.
Cho 8,3 gam hỗn hợp X gồm Al và Fe vào 700 ml dung dịch HCl 1M, sau phản ứng, thu được dung dịch Y và 5,6 lít khí H2 (đktc). Tính % khối lượng mỗi kim loại trong hỗn hợp X và nồng độ mol/l dung dịch Y.
âu 10: Một người phải thực hiện một công 3000J để đưa một vật lên cao trong 10s. Công suất của người đó là? 10 điểm A. 300W B. 200W C. 150W D. 400W
Mọi ng giúp em với ạ, em cảm ơn
Huhu giờ này ai còn onl không ạ>:? Làm giúp em 2 bài này với giải thích rõ ra ạ(((= Xie xie <3 Not spam nha^^
part 6 ( vẽ tự do hoặc các bạn chọn cho mình vài cái avatar anime nữ nhé)
Còn ai thức hông qua đây giúp tui câu 18 mai tui kiểm tra rồi Sẽ hậu tạ
3. Read the paragraph and fill in the gap with one suitable word: All the world knows William Shakespeare as one of the greatest poets and dramatists. He was (1).................in a small English town of Stratford-upon-Avon and (2) ..............up in a large family of eight brothers and four sisters, but many of them died very (3) ................ His father, John Shakespeare, made and sold gloves. William learned (4).....................a school in Stratford. He married very young (5)......................he was about nineteen, and soon (6).............. to London where he worked at a theater. There he began to write (7)................for the theater, his plays were good and people like (8)..................... Now Shakespeare could help his family in Stratford. He (9)........................thirty-seven plays and some books of poems. At the end of his life he came back to Stratford and (10).....................................there. C. WRITING 1. Rewrite each of the following sentences using the CAPITAL word given (do not change the capital words given). 1. They are cutting the cake with a sharp knife. (CUT) ………………………………………………………………………….. 2. I spend half an hour each day doing my homework. (TAKES) ………………………………………………………………………….. 3. Because of the bad weather, we had to stop our picnic. (FROM) ………………………………………………………………………….. 4. My mother cooks well. (A) ………………………………………………………………………….. 5. How far is it from Hanoi to Ho Chi Minh city? (DISTANCE) ………………………………………………………………………….. 2. Write a passage (120 -150 words) to give your idea on the following question: “Why is Nghe An/ Ha Tinh/ your hometown a good destination for tourists?”
1. I don’t like this chair. It’s ________________(COMFORT) 2. What did you learn from your last ___________________? (DISCUSS) 3. Walking is a fun, easy and ____________________ activity. (EXPENSIVE) 4. He often drives_____________so he had an accident yesterday. (CARE) 5. I visit my granny______________a month (ONE) 6. This tree has a lot of yellow_____________ (LEAF) 7. My friend, Nga plays the piano very __________ (BEAUTY) 8. Air ___________ is a big problem in the big cities. (POLLUTE) 9. He always talks on the phone with his friend. He is very _____________ (TALK) 10. My classmate, Tim is the _____________________ player in the team. (BAD) B. READING 1. Read the passage and choose A, B, C or D to complete the paragraph. (1)_________the United States, many adults and children (2)_________overweight. Some people eat (3)_________food at meals. They also eat snacks between meals. Sometimes people eat healthy snacks like fruit or vegetables (4)_________many Americans eat a lot of junk food such as cookies, candy and potato chips. Eating junk food can (5)_________people gain weight. People also gain weight (6)_________they don’t get enough (7)_________. People need to walk, run, ride bicycles, or walk out in health clubs and gyms .When people exercise, they (8)_________good and have more energy. A good (9)_________ and exercise will help you (10)_________ a long and healthy life. 1. A. On B. In C. At D. from 2. A. is B. was C. were D. are 3. A. too many B. too much C. few D. plenty 4. A. but B. because C. although D. so that 5. A. get B. lead C. urge D. make 6. A. so B. however C. but D. because 7. A. exercises B. work C. exercise D. energy 8. A. become B. taste C. have D. feel 9. A. diet B. meal C. food D. health 10. A. to live B. living C. live D. to living 2. Read the passage and choose the best answer to the following questions. Bangkok, the capital of Thailand, is a city of contrasts. It is an exciting, crowded, modern city and, at the same time, a city that is full of history. The streets of Bangkok are usually noisy and have too many people. Some people are selling food; others are selling clothing, cassette tapes, flowers, or souvenirs. Visitors love the river markets, the beautiful temples and architecture, and the nightlife. Most of the year, Bangkok is hotter than any other capital city in Asia, but from December to February, the weather is not as warm and so it is much more comfortable. Actually, it’s an interesting city to visit at any time of the year. The shopping is excellent, and the prices are not as high as in many other large cities in Southeast Asia. There is always so much to do in Bangkok at anytime of the day or night – from watching Thai dancing or boxing to taking a boat trip on the river or trying some of the delicious and spicy food. And if you get tired of the city and want a quiet place, there are beautiful beaches only two hours away by bus. 1. Which phrases can you use to describe the streets of Bangkok? A. a city of contrasts B. noisy and crowded C. full of history D. excited and modern 2. What does NOT interest visitors in Bangkok? A. the shopping B. sightseeing C. the weather D. the nightlife 3. “so much to do in Bangkok” means ____. A. easy to find a job in Bangkok B. much free time C. lot of entertainment D. lot of souvenirs 4. What visitors cannot see or watch at any time of the day? A. Thai dancing B. Thai boxing C. river markets D. nightlife 5. Where is the nearest beach from Bangkok? A. only two hours B. only two hours away C. only two hours from Bangkok D. only two hours away by bus
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