Cho `a + b + c +d = 0` Chứng minh rằng `a^3 + b^3 + c^3 + d^3 = 3(b + c)(ad - bc)` Cần gấp ạ

người ta pha 2l nước với 3l sữa Tính khối lượng riêng cua hốn hợp Bt klr của nước là 1000kg/m3, của sữa là 1200kg/m3

I. Choose A, B, C or D to indicate the correct answer to each of the following questions. 1. Miss Lien ______ in a small house in Hanoi. A. live B. lives C. go D. goes 2. On Mondays, she ______ them grammar. In the evening, she usually ______ at home and listens to music. A. teach, stay B. teaches, stay C. teaches, stays D. teaches, stays 3. He can ______ soccer, tennis and badminton. A. play B. plays C. like D. likes 4. There ______ a lot of trees and flowers in the park. A. is B. are C. be D. being 5. How many rooms does her house ______ ? A. grow B. do C. make D. have 6. I don’t ______ he’s such a boring man. A. like B. hate C. think D. give 7. Living here is so convenient – everything I ______ is just 5 minutes away. A. like B. hear C. love D. need 8. Harry Porter is the movie that she likes best . She always ______ me about the scene and content in this film. A. tells C. says C. does D. gets 9. She ______ studying Math subject because she is very smart. A. like B. likes C. hate D. hates 10. She likes _______ to music and taking care of her family. A. listen B. listening C. hear D. hearing 11. Robots will ______ me do my homework and take care of my dog. A. give B. do C. help D. make 12. We should ______ food that is good for our teeth and our body: milk, cheese, fish, brown bread, potatoes, red rice, raw vegetables, and fresh fruit. A. eat B. drink C. like D. let 13. Nowadays many people just ______ cereal with milk and sugar, opr toast with marmalade, jam, or honey. A. drink B. have C. wear D. feel 14. Some people have coffee, often instant coffee, which is ______ with just hot water. A. liked B. got C. made D. gained 15. Maybe in the future my robot can ______ to me and understand me. A. have B. eat C. get D. talk 16. I usually ______ a lot of housework. A. make B. do C. wash D. watch 17. Ba ______ television in the evening. A. watches B. hears C. listens D. likes 18. My father hates ______ coffee. He prefers tea. A. drunk B. drink C. drinks D. drinking 19. They ______ people from other countries learn more about who they are. A. have B. help C. happen D. get 20. At school, we ______ many subjects. A. have B. get C live D. laugh 21. What about ______ to my house after school? A. get B. getting C. come D. coming 22. I ______ going shopping, whereas my sister ______ staying at home. A. like, like B. like, likes C. likes, likes D. likes, like 23. At the moment we ______ a chemical experiment. A. are doing B. is doing C. are moving D. is moving 24. Both I and my younger brother ______ dogs because we was bitten by a dog. A. like B. likes C. hate D. hates 25. Today is my father’s birthday. I and my sister want to ______ a cake as a present for my dad. A. do B. have C. get D. make

chính : cho nho xin từ khóa để tìm kím kiểu ảnh dưới phụ : calli : tự nhiên seo yêu đời đúng từ khóa + calli đẹp, có tâm = CTLHN ko app

Tìm chu kì tuần T của hàm số Y=sin $\frac{3x}{2}$ + sin $\frac{5x}{x}$

cho 20 điểm câu này thì hơi pro rồi nhe=))) giúp tui cái BT này ik

Bài 1: 1. Visiting small villages in Moc Chau, tourists …… into the locals’ homes and …… with homemade corn wine. A. welcome - treat B. welcomed - treated C. are welcome - treated D. welcomed - are treated 2. Located only 187 kilometres from Ha Noi, Moc Chau ……………… by both private and public transport. A. can easily reach B. can reach easily C. can easily reached D. can be easily reached 3. Our parents …………..… to Moc Chau with us, so we went there on our own. A. were too busy that they went B. were too busy to go C. so busy that they went D. so busy to go 4. I was astonished that Da Nang ……… different from what I had seen 5 years earlier. A. be B. has been C. was D. had been 5. It ………………… to support the victims after the disaster. A. was kind of them B. was kind that they C. was kind of them that they D. was kind that them 6. The Prime Minister was pleased that the traffic problems of the city ………… A. be solved B. have been solved C. to have been solved D. had been solved 7. It is said that Ha Long Bay ………………… one of the most extraordinary natural wonders you have ever seen. A. be B. is C. was D. had been 8. My friends suggest ………………… by train to save money. A. go B. to go C. going D. we will go 9. Linda has lost her passport again. It’s the second time this ………………….. A. has happened B. happens C. happened D. had happened 10. I borrowed four books on gardening the last time I ……..…… to the library. A. go B. went C. had gone D. have gone Bài 2: 1. Before I started the car, all of the passengers ……………… their seat belts. A. will buckle B. had buckled C. buckle D. have buckled 2. No sooner ………………… the house than it started to rain. A. Laura had left B. had Laura left C. was Laura leaving D. Laura left 3. My feet are killing me! I wish I ………………… more comfortable shoes. A. had wore B. were wearing C. wore D. wear 4. The old man is said ………………… his memory. A. to have been lost B. to be lost C. to have lost D. to lose 5. I planned to visit my parents last week, but they suggested ………… the visit for a week because they hadn’t finished decorating the spare room. A. postponing B. to postpone C. to be postponed D. being postponed 6. My mother came from Baffin Island and she ……………… in an igloo. A. used to living B. used to live C. is used to live D. was used to live 7. I wish there ………………… no more family violence in the world. A. is B. were C. will be D. has been 8. Marriages ………………… by parents. A. used to arrange B. used to be arranged C. were used to arrange D. were used to be arranged 9. I wish I ………………… in an international summer camp in Brazil now. A. participate B. would participate C. were participating D. had participated 10. All the students were relieved ………………… the exams. A. that they pass B. that they would pass C. to have passed D. to be passed - nhanh nha-

Tìm Min: `B = x^2 + 2y^2 + 3z^2 - 2xy + 2xz - 2x - 2y - 8z + 2000`

Tìm tập xác định của hàm số lượng giác: 1. y=$\frac{2sinx+1}{cos²x}$ 2. y=$\frac{\sqrt[]{7-sinx}}{cos²x}$

MÌNH chia nhỏ câu hỏi đấy ạ!Mbg giúp toi nhes ^^