Đáp án+Giải thích các bước giải:
b,$\dfrac{\sqrt{3}-\sqrt{6}}{\sqrt{2}-1}-\dfrac{2}{\sqrt{3}-1}+\dfrac{6}{\sqrt{3}}$$=-\sqrt{3}-\dfrac{2\sqrt{3}+2}{2}+2\sqrt{3}$$=\dfrac{2\sqrt{3}-2\sqrt{3}-2}{2}$$=\dfrac{-2}{2}$$=-1$
b) $\frac{√3-√6}{√2-1}$ - $\frac{2}{√3-1}$ + $\frac{6}{√3}$
= $\frac{√3( 1-√2}{√2-1}$ - $\frac{2(√3+1)}{(√3-1)(√3+1)}$ + 2√3
= -√3 - $\frac{2(√3+1)}{2}$ + 2√3
= -√3 - √3 - 1 + 2√3
= -1
Bài 4. Trộn 250 ml dung dịch chứa x(g )ZnCl2 với 150ml dung dịch chứa y(g) Na2C03 ( Phản ứng đủ ) Lọc kết tủa nung được 12,15g rắn . a. Tính x, y b. Tính nồng độ mol /l hai dung dịch muối ban đầu c. Tính nồng độ mol chất trong nước lọc
Hòa tan hoàn toàn 2,16 gam Al vào dung dịch chứa HNO3 (vừa đủ) thu được dung dịch Y chứa 18,64 gam muối và a mol khí N2O. Giá trị của a là?
II. Choose the best answer a, b, c or d to complete the sentence. 1. I went on a trip to the countryside and had my first experience _______ farm work. a.on b. with c. for d. of 2. We usually spend our holiday in the village _______ our grandparents live. a.what b. where c. which d. when 3. I think country life is so boring and _______ because you’re not close to shops and services. a. unhealthy b.inconvenient c. comfortable d. peaceful 4. On the farm, uncle Duong showed us how to _______ cucumbers. a. plough b.produce c. pick d. put up 5. Mongolian children start to learn _______ before they can walk. a. horse riding b.riding horse c. ride horse d. horse ridden 6. On the side of the road, a herd boy was herding _______. a. kites b.hay c. cattle d. blackberries 7. Mongolian children learn to ride when they are _______ as three years old. a. as young b.younger c. younger than d. so young 8. Does your new stereo play music _______ than your old one did? a. louder b.more loudly c. loudlier d. more louder 9. Countryside is not polluted _______ you can breathe there fresh air. a. although b.however c. therefore d. as 10. ‘Children in my village often fly their kites in dry rice fields.’ ‘_______’ a. It’s right up my street! b. That’s awesome. c. Exactly what I want. d. How interesting
5 sao và câu tlhn cho ai nhanh nhất
vẽ mầm mệt NL:ốm nặng quá ko bt có chiu nổi ko '_'
1. They advised him (not/ cross) not to cross_________ the street against the red lights. 2. He and his sister (not/ meet) _________ my friends since last Christmas. 3. She (work) ______ here since she left school? 4. Everyone (read) _______ this novel, let us (discuss) ______ it. 5. I (meet) _met_______ John before I (be) ________ a fortnight in Paris. 6. The children were frightened because the lights suddenly (go) ________ out and they (sit) ________ in the dark. 7. What tune (play)…………….when we (come)…………………… in? 8. She was badly hurt when her car hit another car. If she (wear) ________ her seat belt, she (not hurt) ________ so badly. 9. Although some groups of people (1. always live) _________ outdoors in tents, camping as we (2.know) _________ it today (3. begin) _________ to be popular about 50 years ago. The increase in the use of cars and improvements in camping equipment (4. allow) ________ more people to travel longer distances into the countryside and (5. stay) _________ there in greater comfort. Many campers like (6. be)………….themselves in quiet areas, so they take their tent and food and walk or cycle into the forests or the mountains. Others, (7. prefer) _________ to be near people, (8. drive) _________ to a public or privately-owned campsite which (9. have) ___________ up-to-date facilities like hot shower and swimming pools. Whether campers are separate in the mountain or on a busy site, they should remember to keep the area clean and tidy. In the forests, they must put out any fires and keep food hidden to avoid (10.attract) ………………… animals. giúp em ạ! em cảm ơn
Viết một đoạn văn ngắn trình bày về cái hay của phần trích sau theo kiểu đoạn diễn dịch, khoảng 12 câu trong đoạn có sử dụng câu nghi vấn dùng để bộc lộ cảm xúc và phép thế để liên kết (chủ thích rõ) Nhung mỗi năm mỗi vắng Người thuê viết nay đâu? Giấy đỏ buồn không thảm Mục đọng trong nghiên sầu... Ông đồ vẫn ngồi đấy. Qua đường không ai hay Lá vàng rơi trên giấy; Ngoài giời mưa bụi bay.
calli : I love you , có trang trí nhé NL: Chi tiết dưới bình luận
Giải nhanh hộ ạ .................
II. Use the correct form of the given word to complete each of the following sentences Question 26. The girl always listens __________ to the teacher’s instruction (ATTEND) Question 27. He will never forget his memorable ____________ (CHILD) Question 28. He was punished for his __________ (LAZY) Question 29. There is a need for greater _________ (DIVERSE) and choice in education Question 30. These mechanics work in a car repair ___________ (WORK). Question 31. My outgoing ___________ (PERSON) has definitely helped me succeed. Question 32. The pregnant woman talked with her husband about their _____________ (RESPONSIBLE) Question 33. They finally came to a mutually __________ (BENEFIT) agreement. Question 34. Runners are encouraged to carry __________ (FILL) water bottles Question 35. She is a __________ (LEAD) expert on the country’s ecology III. Use the correct form and tense of the verb in brackets to complete each of the following sentences Question 36. My friend is a very careful student. He often ___________ (36. check) his writing twice before ____________ (37. give) it to the teacher (ĐIỀN CÂU 36) Question 37. My friend is a very careful student. He often ___________ (36. check) his writing twice before ____________ (37. give) it to the teacher (ĐIỀN CÂU 37) Question 38. Someone (38. wait) __________ for you outside. Who is that? Question 39. When Carol (39. call) __________ last night, I (40. watch) __________ my favorite show “The running man” on television (ĐIỀN CÂU 39) Question 40. When Carol (39. call) ___________ last night, I (40. watch) ___________ my favorite show “The running man” on television (ĐIỀN CÂU 40) Question 41. I hate ________ (41. laugh) at by my friends. Question 42. It’s 7.00 o’clock. Hurry up or you _______ (42. be) late for school. Question 43. If I were Brad Pitt, I _______ (43. not stay) in this slum Question 44. My father ___________ (44. retire) by the year 2020. Question 45. I hope your father __________ (45. remember) to collect your birthday cake tomorrow evening
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