Cho a,b;c>0 tm: a+b+c=3 CM: $\frac{a^{3} }{(a+1)(b+1)}$ + $\frac{b^{3} }{(b+1)(c+1)}$ + $\frac{c^{3} }{(c+1)(a+1)}$$\geq$ $\frac{3}{4}$

Giúp mk câu c thôi ạ ko cần vẽ hình hay lm câu a,b cũng đc hứa sẽ vote 5* + câu trả lời hay nhứt ạ ^^ Cho tam giác ABC nhọn có 2 đường cao BC và CF a. CMR : AD.AC=AE.AB b. CMR : góc AED = góc ACB c. gọi H và K lần lượt là hình chiếu của B và C lên đường thẳng DE CMR : HE=DK

31. We started to study English four years ago. We have ____________________________________________ 32. We took a train to Liverpool last Saturday We got ____________________________________________ 33. We stop the football match because of the bad weather. Because the weather ____________________________________________ 34. Jone plays chess better than Mike. Mike doesn’t ____________________________________________ 35. Her book is the same as mine. Her book is ____________________________________________ 36. What was your height last year? How ____________________________________________ 37. How much is the blue schoolbag? What is ____________________________________________ 38. How much does a box of chocolates cost ? What ____________________________________________ 39.Let’s walk to school! Why ____________________________________________ 40. How much does a box of chocolate cost? What ____________________________________________? 41. Does your father cycle to work? Does your father get ____________________________________________? 42. I last saw her two months ago I ____________________________________________ 43. Why don’t we take a trip to Ho Chi Minh city this Tet holiday? What ____________________________________________Ho Chi Minh city this Tet holiday? 44. The beach is close to the hotel, so we can walk there. We can go ____________________________________________because it’s close. 45. I last saw Peter five month ago . I haven’t ____________________________________________ 46. How much is a bottle of water? What ____________________________________________? 47. Let’s dance and sing a song. What about ____________________________________________? 48. How high is the Mount Everest? What ____________________________________________? 49. He often flies to Lon Don. ____________________________________________ 50. This film is more interesting than that one. That film is ____________________________________________

Giúp mk vs ạ hgfđggggggggggggbnnnnnnnbbbhhhhhhhh

𝐂â𝐮 𝟏.[NB] Biểu thức nào sau đây không là đơn thức∶ A. 4x3y(− 3x ) B. 1+ 𝑥 C. 2xy (− x3 ) D. 17𝑥2.(−13)𝑦3 𝐂â𝐮 𝟐.[𝐓𝐇] Tích của hai đơn thức 2x2yz và (−4xy2z)bằng∶ A. -8x3y3z2 B. -8x3y3z C. -6x2y2z D. 8x3y2z2

16. Our resources of energy will soon end because we won’t try to save it. If __________________________________________________________ 17. She likes to live in the countryside. She enjoys __________________________________________________________ 18. __________________________________________________________? The new programme often finishes at eight o'clock. 19. It is necessary for us to be present at the class discussion on Saturday. We must 20. I find it difficult to find a better solution to that problem. I have 21. How much is this hat? How much does ____________________________________________? 22. Why don’t we sing an English song? What about ____________________________________________? 23. What’s your father’s weight? How heavy ____________________________________________? 24.Doing exercises every morning is good for you. It ____________________________________________ 25. Lan likes playing tennis the most. Tennis ________________________________________ 26. My brother plays the guitar very well. My brother is ___________________________________ 27. Nick has never been to Da Nang before. This is _________________________________________ 28. Miss Lan teaches us Vietnamese everyday. ____________________________________________ 29.He is going to saty in Hanoi for a week. ____________________________________________ 30. It takes me fifteen minutes to walk to school. ____________________________________________

Sục từ từ khí $\rm CO_2$ vào $\rm 600ml$ dung dịch gồm $\rm KOH$ $\rm 0,15M$ và $\rm Ca(OH)_2$ $\rm 0,2M$ $\rm a)$ Lập luận và vẽ đồ thi biểu diễn số mol kết tủa phụ thuộc vào số mol khí $\rm CO_2$ hấp thụ. $\rm b)$ Tính số mol khí $\rm CO_2$ bị hấp thụ khi khối lượng kết tủa thu được là $\rm 6g$

Đặt câu hỏi cho phần đc gạch chân : 1. They spent two hours looking for your house => 2. They had an exam last week =>

Giúp tớ nhanh ạ!! Ko cần giải thích

Trong các hình sau: hình chóp đều, hình chóp cụt đều, hình lăng trụ đứng, hình hộp chữ nhật, hình lập phương, có bao nhiêu hình có mặt bên vuông góc với mặt đáy?