`(2x-1)(x-1)(x-3)(2x+3)+9`
`=[(2x-1)(x-1)].[(x-3)(2x+3)]+9`
`=(2x^2-2x-x+1)(2x^2+3x-6x-9)+9`
`=(2x^2-3x+1)(2x^2-3x-9)+9`
Đặt `2x^2-3x+1=t`
`t.(t-10)+9`
`=t^2-10t+9`
`=t^2-9t-t+9`
`=t(t-9)-(t-9)`
`=(t-9)(t-1)`
`=(2x^2-3x+1-9)(2x^2-3x+1-1)`
`=(2x^2-3x-8)(2x^2-3x)`
`=x(2x^2-3x-8)(2x-3)`
-------------------------
Phương pháp đặt ẩn phụ
Đáp án+Giải thích các bước giải:
`=(2x^2-3x)^2-9(2x^2-3x)+(2x^2-3x)-9+9`
`=(2x^2-3x)^2-8(2x^2-3x)`
`=(2x^2-3x)(2x^2-3x-8)`
`=x(2x-3)(2x^2-3x-8)`
Viết năm câu với mệnh đề danh nghĩa. giúp mình với mình cần gấp , cảm ơn nhiều ạ
gấp gấp!!!!!!!!!!!!!!!!! giúp mik vs!!!!!!!!!!!!!!
giải thích giúp mình tại sao câu này lại được đáp án A ạ!
Làm hộ mk vs ạ! Mk sẽ vote và cám ơn cẩn thận- Chúc mn sức khoẻ và học tốt
[x-y+(3 căn x)+(3 căn y)]/[(căn x)- (căn y)+3]
Giúp mình gấp với mình vote 5* I. Choose the words whose underlined part is pronounced differently from that of the others in each group 6. A. limestone B. pilgrim C. rickshaw D. citadel 7. A. geological B. imagine C. agency D. together 8. A. wonder B. complex C. backdrop D. proper 9. A. historic B. picturesque C. enter D. sentence 10. A. plumber B. sculpture C. measure D. structure Bài 1: Chuyển các câu sau sang thể bị động 1. Everyone told us that you were the winner of the City Olympic Prize in the competition last year. 2. Staff reported that the orders were canceled by negative comments. 3. Someone inform me that our manager is going to move to New York. 4. The supervisor announced that the workshop was delayed about 2 hours because of mechanical problems. 5. My father discovered that this plant was grown in India
Với x thuộc Q tìm giá trị nhỏ nhất của biểu thức (x-1/2)^2+10
Choose the one word or phrase -a, b, c, or d- that best completes the sentences. 16. If the technology _______ available, we would be able to expand the business. a. would become b. were become c. had become d. Became 17. If the North Sea _______ in winter, you could walk from London to Oslo. a. happened to freeze b. froze c. should freeze d. should happen to freeze 18. It would have been a much more serious accident _____ fast at the time. a. was she driving b. had she been driving c. she had driven d. if she drove 19. If you _______ to my advice in the first place, you wouldn't be in this mess now. a. listen b. will listen c. had listened d. listened 20. I'll give you a lift if it _______. a. is raining b. rained c. will rain d. had rained 21. If I _______ a more reliable car, I ' _______to Spain rather than fly. a. would have - would drive b. had - had driven c. had - would drive d. would have had - would drive 22. I _______ you sooner had someone told me you were in the hospital. a. would have visited b. had visited c. visited d. visit 23. They couldn't decide _______ it was worth re-sitting the exam. a. if b. whether c. if or not d. whether not 24. _______ how difficult the job was, I mightn't have taken it. a. If I know b. If I would know c. Did I know d. Had I known 25. ____ in my seventies and rather unfit, I might consider taking up squash. a. Were I not b. Was I not c. Weren't I d. If I am not C. Identify the one underlined word or phrase -A, B, C or D-that must be changed for the sentence to be correct. 26. Some scientists believe that the earth have resources enough A B to support its population. C D 27. The population of the world has been increased faster and faster. A B C D 28. Ninety-seven percent of the world' water is saltwater is found in A B C the oceans of the Earth. D 29. Hadn't he resigned, we would have been forced to sack him. A B C D 30. John lived in New York since 1960 to 1975, but he is now living in A B C D Detroit.
Lm hộ mik với !!!! gấp gấp!!!!!!!!!!!!!!!!!
giúp mình câu này nha càng sớm càng tốt nhớ trả lời hết mình nhá
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