Cho tam giác ABC vuông tại A , AD là đường cao , đương fphân giác của góc B cắt AD tại , AC lần lượt tại F và E. Chứng minh rằng DF/FA=AE/EC

e. (2x – 5)2 – (x + 2)2 = 0 A. S = {1; -7} B = {1;7} C. S = {-1; -7} D.S = {-1; 7} f. x2 – x – (3x – 3) = 0 A. S = {-1; -3} B = {-1; 3} C. S = {1; 3} D.S = {1; -3} Bài 23/17.SGK a. x(2x – 9) = 3x(x – 5) A. S = {0; 6} B = {0;-6} C. S = {1; 6} D.S = {6; 0} b. 0,5x(x – 3) = (x – 3)(1,5x – 1) A. S = {-1; -3} B = {-1; 3} C. S = {1; -3} D.S = {1; 3} c. 3x – 15 = 2x(x – 5) A. S = {-5; -3/2} B = {-5; 3/2} C. S = {5; 3/2} D.S = {5; -3/2} d.3/7x-1=1/7x(3x-7 A. S = {1; 7/3} B = {-1; -7/3} C. S = {1; -7/3} D.S = {-1; 7/3} Bài 24/17.SGK a. (x2 – 2x + 1) – 4 = 0 A. S = {-1; -3} B = {-1; 3} C. S = {1; 3} D.S = {1; -3} b. x2 – x = -2x + 2 A. S = {-1; -2} B = {-1; 2} C. S = {1; 2} D.S = {1; -2} c. 4x2 + 4x + 1 = x2 A. S = {-1; -1/3} B = {-1; 1/3} C. S = {1; 1/3} D.S = {1; -1/3} d. x2 – 5x + 6 = 0 A. S = {-3; -2} B = {-3; 2} C. S = {3; 2} D.S = {3; -2} Bài 25/17.SGK: (Trình bày lời giải) a. 2x3 + 6x2 = x2 + 3x A. S = {0; 3; -1/2} B = {0; -3; 1/2} C. S = {0; -3; -1/2} D.S = {-3; 1/2} b. (3x – 1)(x2 + 2) = (3x – 1)(7x – 10) A. S = {1/3; -3; 4} B = {-1/3; 3; 4} C. S = {1/3; 3; -4} D.S = {1/3; 3; 4} các bạn giúp mình nếu các bạn ko làm câu nào đó hãy bỏ qua

Các chất khí : So2,O2,Co2,N2 nặng hay nhẹ hơn khí hidro bao nhiêu lần? ( Cho: S=32 ; C=12 ; O=16 ; N=14 ; H=1

Sinh sản hữu tính là hình thức sinh sản: Hình thành cá thể mới từ một phần của cơ quan sinh dưỡng. Có sự tham gia của cây bố và cây mẹ. Có sự kết hợp giữa tế bào sinh dục đực và tế bào sinh dục cái. Có sự kết hợp giữa tế bào sinh dục đực và tế bào sinh dục cái. Có sự tham gia của cây bố và cây mẹ.

giai pt ???????????/////////////

là học sinh em cần có thái độ như thế nào trong tình yêu và hôn nhân

cho đoạn thơ Bác nằm trong giấc ngủ bình yên Giữa một vầng trăng sáng dịu hiền Vẫn biết trời xanh là mãi mãi Mà sao nghe nhói ở trong tim Phương thức biểu đạt hai câu mở đầu đoạn thơ là gì?

So sánh m và n biết a)-1/2m>-1/2n b)3m+1<3n+1

EXERCISES A. PERSONAL HYGIENE I. Điền vào chỗ trống các từ thích hợp: health personal hygiene harvest helpful strange carefully 1. Farmers are very busy during ……………… 2. You should wash regularly to ensure …………… 3. Swimming is good for your …………… 4. My father always drivers …………… 5. She always helps her mother do the housework. She’s very …………… to her mother. 6. He’s a new student. Everything is ……………to him. II. Điền từ vào chỗ trống: What When Where How Who How often What time 1. ………………… does she iron her clothes? – On Sundays. 2. ………………… did you do last weekend? – I went fishing with my father. 3. ………………… do you clean your room? – Three times a week. 4. ………………… helped Hoa make her skirt? – Mrs. Mai. 5. ………………… did Ba eat his breakfast this morning? – At half past six. 6. ………………… did your father go last night? – He went to my grandparents’ house. 7. ………………… did you buy this dress? – Yesterday morning. 8. ………………… does Nam go to school? – By bike. III. Chọn đáp án đúng: 1.………you do your homework last night?- Yes, I did. A. Do B. Did C. Are D. Will 2. He ………to the zoo last Sunday. A. goes B. went C. is going D. will go 3. Hoa’s mom wants her …………. exercises regularly A. do B. did C. does D. to do 4. ………. are Hoa’s parents busy? - Because it’s harvest time now. A. What B. Why C. When D. How IV. Đổi các câu sau sang thể phủ định và nghi vấn: 1. Mary was happy at school yesterday. (-)……………………………………………………………………………….. (?)……………………………………………………………………………….. 2. Hoa received a letter from her mom last week. (-)……………………………………………………………………………….. (?)……………………………………………………………………………….. V. Sắp xếp những từ sau thành câu có nghĩa: 1. how/ Hoa/ yesterday/ a/ use/ sewing/learned/ machine/ to/. ……………………………………………………………………………….. 2. stay/ candy/ too/ up/ eat/ don’t/ much/ and/ late/. ……………………………………………………………………………….. 3. exercises/ regularly/ to/ healthy/ keep/ take/ stay/ morning/fit/. ……………………………………………………………………………….. VI. Chia động từ trong ngoặc: Yesterday (be)………… Sunday, Nam (get)………… up at six. He (do)………… his morning exercises. He (take)………… a shower, (comb)………… his hair, and then he (have)…………… breakfast with his parents. Nam (eat)…………… a bowl of noodles and (drink)………… a glass of milk for his breakfast. After breakfast, he (help)…………… Mom clean the table. After that, he (brush)………… his teeth, (put)………… on clean clothes, and (go)………… to his grandparents’ house. He (have)…………… lunch with his grandparents. He (return)………… to his house at three o’clock. He (do)………… his homework. He (eat)…………… dinner at 6.30. After dinner, his parents (take)………… him to the movie theater. It (be)………… a very interesting film. They (come)………… back home at 9.30. Nam (go)………… to bed at ten o’clock.

I. READING: (5pts) A. Choose the best answer for each numbered blank.(2pts) Water pollution is the contamination of bodies water such as (1)_______________, rivers, oceans, and groundwater (the water beneath the Earth's surface). It is one of the most serious types of pollution. Water pollution can have many different causes. Factories dump industrial waste (2) ________________ lakes and rivers. Sewage from households is another cause. Farms using (3) _________________ to kill insects and herbicides to kill weeds can also lead to water pollution. These factors cause ‘point source’ pollution while (4) ______________ from storm water and the atmosphere result in ‘non-point source' pollution. (1) A. streets B. lakes C. buildings (2) A. to B. onto C. into (3) A. pesticides B. herbicides C. waste (4) A. pollutants B. polltion C. polluted B. Read the text , then answer the questions.(3pts) The Land of Oz Kim is from Korea. She and her parents are leaving for Australia on vacation. Their flight from Seoul to Sydney is boarding now. Australia is enormous. It’s a country and a continent. Australians speak English, but they have their own slang. Australians are called Aussies, their country is Oz, and they have forty different kinds of roos (kangaroos). The word kangaroo is native Australian. There are also lots of things to do Australia. In Sydney, there is the famous Opera House, and there are beautiful beaches. In the northeast, there is the Great Barrier Reef. Visitors can snorkel. There is also Ayers Rock in the center of the country. It’s a very big rock, 345 meters tall and 3 kilometers long. Kim is very excited about her trip to all these wonderful places. Choose the best answer for each question: 5. Where are Kim and her parents going on vacation ? A. They are going to Australia on vacation. B. They are going to Korea on vacation. C. They are going to England onn vaccation. 6. What can visitors do at the Great Barrier Reef ? A. They can swim. B. They can snorkel. C. They can walk. 7. How does Kim feel about her trip ? A. She feels boring. B. She feels tired. C. She feels excited. A 8. How big is Ayers Rock in the center of the country ? A. 345 meters long and 3 kilometers tall. B. 345 meters tall and 3 kilometers long. C. 354 meters tall and 3 kilometers long. 9. Is Australia a country and a continent ? A. Yes, it is B. No, it isn’t C. Yes, they are 10. What language do the Australian speak ? A. Australian B. English C. French II.WRITING: Choose the sentence that has the same meaning as the first. (5pts) 11. Herbicides lead to point sourse pollution. A. Point sourse pollution happens due to herbicides. B. Point sourse pollution causes herbicides. C. Herbicides pollute the pointed sourse. 12. Those ships have spilled oil in oceans and rivers, so the water is polluted. A. Oceans and rivers are polluted because of oil. B. Oil from those ships results in water pollution in oceans and rivers. C. Ships in oceans and rivers pollute the water. 13. The trees are dead due to the acid rain. A. If the rain had acid, it wouldn’t make the trees die. B. The acid rain occurs because of the trees. C. The acid rain makes the trees die. 14. The cattle station in Australia is larger than that in Belgium. A. The cattle station in Belgium is the largest in the world. B. The cattle station in Belgium is not as large as that in Australia. C. The cattle station in Australia is the largest in the world. 15. They offer the flights to Canada daily. A. The flights are offered by Canadians every day. B. The flights to Canada are offered. C. The flights to Canada serve every day. THE END.