Đáp án+Giải thích các bước giải:
`-4x^2-12x`
`=-(2x)^2-2.2x.3-9+9`
`=-[(2x)^2+2.2x.3+3^2]+9`
`=-(2x+3)^2+9`
Vì `(2x+3)^2>=0`
`=>-(2x+3)^2+9<=9`
Dấu `=` xảy ra khi `2x+3=0<=>x=-3/2`
Vậy `GTLNN=9` khi `x=-3/2`
~ Bạn tham khảo ~
Ta có :
`-4x^2 -12x`
`= -(4x^2 + 12x + 9) + 9`
`= -(2x+3)^2 + 9`
`<= 9`
Dấu "=" xảy ra `<=> 2x+3=0`
`<=> x = -3/2`
Vậy `MAX=9<=> x=-3/2`
Giải giúp mình với nha mình cảm ơn nha bài toán này mình cần gấp
vt thành Câu giàn tiếp 7."Can I use your mobile, John?" asked Sarah. 8."Did you go to Lisbon last year?" Luis asked Paul. 9.“ Have you seen the new film?” he asked Lan 10. “ Are you enjoying yourself ? “ Tam asked me 11. “ Ought the light to be on ? “Hoa asked me 12.“ Does she always wear this blue dress when she is at school ? “Hoa asked me 13.“ Will the taxi be here at seven o’clock, Tam? “ she asked 14. “ Shall I do it before tomorrow ? “ she asked 15. "Are they playing the piano here now, Lan?" she asked. 16. " Do your sons often give you some flowers on your birthday ?" he asked Lan . 17. "Should you have a rest now, little boy? " asked Bob. 18."Can I use your mobile, Ha ?" asked Mai. 19."Have your parents lived here for ten years ?" her mother asked me 20."Is this your hat ? “ asked Ngan. 21."Will you sing some songs in my birthday next Sunday, Tim?" asked Letizia. 22."Are they French or Canadian?," asked Mr . Tan . 23.She said, “Can you speak English, Minh ?” 24.Thanh said to her teacher, “Will I finish my exercise at home ?” 25.Nien asked Hoa, “Do you have many friends ?” 26.My friend said, “Are you going to leave tomorrow ?”- 27. John said, “Is Phong Nha cave in Southern Vietnam ?” 28.I asked Nam, “Are you free tonight ?” 29.She asked the tourists, “Do you know the way to the station ?” 30.Daniel said to Tim, “Is there a cafe nearby ?
Giúp mình với ạ, mình cảm ơn nhiều!
I want you to write the essay on "development of viet nam nowadays"...........(depend)
Mong các bạn giải giúp mình bài này, nghi mãi ko ra
VI. Read the following text about Bill Gate, the co-founder of Microsoft, and choose the best answer. (2.0ms) Bill Gates is the co-founder of Microsoft, the world’s largest PC software company. He is among the richest people in the world. Bill Gates’ interest in computers started when he was a teenager. After high school, he was accepted to several top colleges in the USA: Harvard, Yale, and Princeton. He chose to go to Harvard to study law. At Harvard, he focused more on his interest in computer than on coursework. He often relaxed by playing video games in Harvard’s computer lab. He left Harvard before graduating because he wanted to open a software company with his friend Paul Allen. However, he later said “ I don’t think dropping out is a good idea.” In 2007, he received an honorary degree from Harvard. He began his speech by saying this to his father in the audience. “I’ve been waiting more than 30 years to say this: Dad, I always told you I’d come back and get my degree.” Bill Gates is no longer working full time for Microsoft. He is now, with his wife, running The Bill & Melinda Gates Foundation which aims to improve healthcare, reduce poverty, and promote education around the world. 1. When did Bill Gates first develop his interest in computers? ……………………………………………………………………. 2. What did he study at Harvard University? ………………………………………………………………………. 3. What did he often do to relax while at Harvard? ……………………………………………………………………….. 4. Why did he drop out of Harvard? …………………………………………………………
Khối lượng m=500g , dao động điều hoà với năng lượng E=0,025 J . Tại vị trí x=3cm thù vận tóc của vật là v=-8pi cm/s . Xác định tần số góc với vật với pi2=10
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Giá sách bạn Yến gồm có sách giáo khoa và sách đọc thêm.1/3 số sách là sách đọc thêm,còn lại là 12 quyển sách giáo khoa.Hỏi bạn Yến có mấy quyển sách đọc thêm
Vẽ một bà tiên có đôi cánh trắng, xinh đẹp, đồngte, tốt bụng, nhân hậu và vị tha, bay đến khắp nơi cứu giúp chúng sanh qua kiếp khổ kiếp nạn, mang lại cuộc sống ấm no, hạnh phúc cho mọi người (như Tiên vậy)
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