Bài 6: Cho tam giác ABC cân tại A. Các đường phân giác trong của hai góc B và góc C cắt các cạnh đối diện lần lượt tại D và E. a) Chứng minh tam giác BEC = tam giác CDB. b) Chứng minh tam giác AED cântại A c) Chứng minh tam giác BED và EDC làcác tam giáccân . d) ChứngminhBE=ED=DC

Bài 03: Gọi Ot, Ot' là hai tia nằm trên cùng một nửa mặt phẳng bờ là đường thẳng xy đi qua O. Biết xOt = 300, yOt' = 500. Tính yOt, yOt'. Bài 04: Gọi Ot, Ot' là hai tia nằm trên cùng một nửa mặt phẳng bờ là đường thẳng xy đi qua O. Biết xOt = 800, yOt' = 600. Tính yOt, yOt'.

c) 16: x^2= x:(-4) d) x:0,27= 3:x

Cho tam giác ABC vuông tại A (AB>AC) M là trung điểm BC.Trên tia đối của tia MA lấy D cho MD=MA. a) chứng minh AB=DC và AB//DC b) chứng minh tam giác ABC=tam giác CDA từ đó suy ra AM=BC/2 c) trên tia đối của tia AC lấy E sao cho AE=AC. Chứng minh BE//AM d) tìm điều kiện của tam giác ABC để AC=BC/2 e) gọi o là trung điểm của AB.chứng minh ba điểm E, O, D thẳng hàng. Giúp mình nha!!!

nêu những hoạt động của hội việt nam cách mạng thanh niên từ 1925 đến 1929

Quangcuong giúp em bài này với Bài 4: Cho 4,8g Mg tác dụng với 100ml dd H2SO4 6M. Tính nồng độ mol các chất trong dd sau pứ? Bài 5: Cho 7,2 g FeO tác dụng với 200g dd HCl 10,95%. Tính nồng độ % các chất trong dung dịch sau pứ? Bài 6: Cho 5,4 g Al pứ với 500 g dd HCl 14,6%. Tinh C% các chất trong dd sau pứ

Bài 3: Cho đơn thức A = (-3/4.x^2.y^3.z).(-16/9.xyz^4) a) Thu gọn đơn thức A. b) Xác định hệ số và bậc của đơn thức A. c) Tính giá trị của A tại x = 3; y = 1; z = -1

Cho tia tới SI hợp với gương phẳng GP một góc 50 0 như hình vẽ: a/ Hãy vẽ tia phản xạ và hãy tính hợp bởi tia tới và tia phản xạ. b/Giữ nguyên tia tới SI , muốn thu được tia phản xạ có phương thẳng đứng chiều từ trên xuống dưới thì đặt gương như thế nào? ( vẽ hình) nhanh lên giùm nhé

Các chị xinh đẹp Các anh xinh trai Xin hãy giúp em phần a và phần c có đc ko Các anh chị ơi

V. Write full sentences, using the words or phrases provided. You can add some words or make suitable changes. 39. Traffic jam/ one/ most common/ issue/ big city/ world. …………………………………………………………........................ 40. There/ many/ people/ use/ road/ and/ one/ main reason/ cause/ traffic/ jam. ................................................................................................................ 41. We/ solve/ traffic problem/ by/ encourage/ people/ use/ bicycle/ rather/ car/ short trip. ................................................................................................................ 42. People/ use/ public transports/ reduce/ number/ private vehicles/ road. ................................................................................................................ 43. Move/ big company/ factory/ city/ countryside/ help/ reduce/ traffic jam. ............................................................................................. .................................. 44. All streets/ wide/ and traffic lines/ more logical. ................................................................................................................ 45. Heavy penalties/ use/ those/ who break the traffic law. ................................................................................................................ VI. Find and correct a mistake in each sentence 46. Use roads careful so we may be able to use them for a long time. A B C D 47. I sawsome cars stop by the police. A B C D 48. The carwas too expensive for him buying. A B C D 49. My father is a careful driver and he doesn’t drive too fast or dangerous. A B C D 50. On the way we passed, there were many interested sights. A B C D 51. The old house in the end of the road has been sold. A B C D 52. Despite oftaking a taxi, he arrivedlate. A B C D 53. The gate are closedso that the children can’t runinto the road. A B C D 54. The train had just left when I arriveatthe station. A B C D 55. It is important to learnuse the roads properly and safely. A B C D 56. I see a serious accident while I was standingat the bus stop. A B C D VII. Give correct word form 57. It is _____________ to keep your headlights on 24 hours a day in Sweden. NECESSITY 58. For bike _____________, make sure bikes have working brakes. SAFE 59. Small children should have special seats for their own _____________ while they are in a car. SECURE 60. _____________ and motorists need to be able to judge speed and distance accurately on the road. CYCLE 61. Passengers are now permitted to _____________ your seatbelts because we are all on board. FASTEN 62. _____________ obey traffic signals. STRICT 63. You can’t drive this way because that sign says car _____________. PROHIBIT 64. In Maryland, USA, it is _____________ to curse in public. LEGAL VIII. Read the text and answer the questions below Richard Ryan is stuck in traffic. There must be an accident somewhere up ahead because he's been sitting in the same spot for the last few minutes. The cars aren't moving at all. It looks like it's going to be another slow commute. Even though he left his house early to beat the traffic, if the cars don't start to move soon, Richard will be late for a very important meeting. He has to meet with some lawyers who are advising his company on a construction project. Richard is the president of a big company. If he's late, he won't get in trouble, but he hates to be late for anything. Sergey is stuck in the same traffic jam, and he's headed to the same meeting that Richard is going to. He's worried about being late, so he gets out his cell phone and calls one of his coworkers to tell her that traffic is bad. Sergey doesn't know that his boss, Richard, is in the same traffic jam. If he knew that, he wouldn't be so tense. Sergey has a reputation for being late to work. He always blames it on the traffic. Everyone tells him he has to leave his house earlier to beat the rush. Sergey likes to stay out late at night, so it's not easy for him to wake up early. Both Richard and Sergey live in California where traffic congestion and delays are common problems. Richard is thinking about moving his business to a new location that's closer to the downtown business district where most of his employees live. If he did that, Sergey could ride his bike to work and forget about getting stuck in a traffic jam. 65. What is most likely the reason why Richard Ryan is stuck in traffic? 66. Which position of Richard Ryan in his company? 67. What are Richard and Ryan heading? 68. Why does Sergey call his co-workers? 69. What could Sergey do if Richard moved his business to where most of his employees live?