`n=(x+1)(x+2)(x+3)(x+4)+1`
`=(x+1)(x+4)(x+2)(x+3)+1`
`=(x^2+5x+4)(x^2+5x+6)+1`
`=(x^2+5x+5-1)(x^2+5x+5+1)+1`
`=(x^2+5x+5)^2-1^2+1`
`=(x^2+5x+5)^2`
Vậy `n` là số chính phương với mọi giá trị của nguyên `x`
Đáp án:
Giải thích các bước giải:
ây dô tiết mục vẽ mầm đây:)) mại dzô vẽ mầm cười ha, tại nãy toy cười vì có một người ko chụp đc slot:)) - Đc chưa:)
Trong word, khi chọn những đoạn văn bản không liền nhau ta sử sụng phím ?
Viết bài văn (từ 2 trang trở lên) về tinh thần phòng chống dịch bệnh covid-19 ở địa phương em
Giúp em bài này với ạ em cảm ơn
$\frac{2+x}{2-x}$ +$\frac{4x²}{x²-4}$+$\frac{2-x}{2+x}$
Vẽ anime/chibi Chép thì gửi kèm tranh gốc nhé :3
vì sao mỗi chất có tính chất nhất định không đổi
Giúp nhanh nhé,mk cần gấp ạ 14. The _______ of Mount Pinatubo in 1991 was one of the worst natural disasters. A. cyclone B. earthquake C. eruption D. damage 15. The meeting is _________8 a.m and 10a.m. A. on B.from C. at D. between 16. She asked me if I ________out the following day. A. went B. go C. to go D. would go 17. The flat looks _______and _______comfortable. A. nicely/ extremely B. nice/extreme C. nicely/extreme D. nice/extremely 18. The bridge __________in 1999. A. built B. is built C. was built D. builds 19. This school is ready_________good citizens for society. A. to provide B. provide C. providing D. provided 20. The boy is so lazy. His parents wish he _________ harder. A. work B. to work C. working D. worked 21. Have you ever seen Picasso’s La Guerre, ________ is really a masterpiece? A. who B. which C. that D. they 22. They were having dinner _________ I arrived. A. what B. when C. while D. how 23. Your little sister has never traveled by bus, ________? A. does your B. does she C. doesn’t she D. has she 24. “Make yourself at home” - “______________” A.That’s very kind.Thanks. B. Not at all C. Yes. Can I help you? D. The same to you IV. Choose the word (A, B, C or D) that best fits the blank space in the following passage. (lpt) In my opinion, it is important to have a day to celebrate for our parents. Children will have a special day to express their feelings, memories (25)________ love for their parents. We have (26)________ opportunity to enhance family traditions. Members of families can have a chance to get together, to know one another and to help one another. On that day, children should give their parents flowers, send them cards, or bring them a special cake and serve them the food (27)________they like best. I believe the idea will be supported and the day will (28)________ nationwide . Everybody loves and wants their parents to be happy. 25. A. because B. but C. so D. and 26. A. a B. an C. the D. once 27. A. where B. who C. whom D. that 28. A. be celebrated B. held C. be done D. take V. Read the following passage and answer the questions. (1pt) The large movement of earth under the water causes a very large and powerful tsunami. The tsunami was called the Asian Tsunami in most of the world. It was called the Boxing Day Tsunami in England, Australia, South Africa and Canada because it happened on the holiday they call Boxing Day. The tsunami caused a lot of damage to countries such as Philippines, Thailand, Indonesia and Sri Lanka. Waves as high as 30m killed many people and damaged or destroyed a lot of buildings and other properties. Over 225,000 people died or were not found after the Tsunami. The wave traveled as far away as South Africa (8000km) where as many as 8 people died because of high water caused by the wave. Because of how much damage was caused and the number of people the earthquake affected, over $ 7 billion was donated to help the survivors and rebuild the areas damaged. 29. Why was the tsunami called the Boxing Day Tsunami in England? A. Because it happened when people were boxing. B. Because it happened when people were making boxes. C. Because it happened on Boxing Day. D. Because it destroyed a lot of boxes. 30. How high were the waves? A. Thirteen meters B. Eighteen meters C. Thirty meters D. Two hundred and twenty-five meters In most of the world, what do they call the tsunami? the Boxing Day B. the Asian Tsunami C. Waves D.survivors Some people in South Africa were killed by__________ A. high water B.buildings C. other properties. D. the earthquake
tác giả văn bản thuế máu nhận xét về yếu tố biểu cảm trong đoạn trích được học
Question V. Choose the underlined word or phrase (A,B, C or D) that needs correcting. 1. My sister enjoys read about wild animals and natural mysteries. A B C D 2. Mr. Thach who sing English songs very well is my teacher of English. A B C D 3. My brother enjoys to go to the park on Summer evenings. A B C D 4. Nam wishes he can speak English fluently. A (When)/A B C D he came, I watched a football match on TV. B C D 5. 6. This is the first time I visited a famous place in Hanoi. A B C D
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