rút gọn B = (x^2-2xy)^3+3(x^2-2xy)^2y^2+3(x^2-2xy)Y^4+y^6

IV. Use the correct tense (simple past or past continuous) 1.When we were in Canada, we …………..skiing almost every day. (GO) 2.About four years ago I …………….to become a restaurant manager. (DECIDE) 3.When I was younger I ……………..pizza almost every day (EAT) 4.George ………………..a shower when someone suddenly …………….at the door. (HAVE, KNOCK) 5.Jimmy and I ……………..from the house to the taxi because it …………..heavily (RUN, RAIN) 6.Two men …………….outside so I went to see what it was (ARGUE) 7.At midnight I ……………….but Mary …………………to music (SLEEP, LISTEN) 8.Daniel …………………you yesterday afternoon, but you weren't around (CALL) 9.Penny ……………….to catch the bus when she …………..and ………………down (RUN, SLIP, FALL) 10.We ………………breakfast when the message ……………… (EAT, COME) 11.I ………………..about my favourite dish when the alarm clock ………..off (DREAM, GO) 12.While I ……………for tomorrow's game , a neighbour ……………to visit me (PRACTICE, COME) giup minh voi a

Use the correct form of the verbs in the parentheses. 1. My father gave up …………….( smoke ) three years ago. 2. Would you mind ………..( keep ) silent ? I’m trying ……………( study ). 3. I always try to avoid……………………( borrow ) money from my friends. 4. The traffic was very heavy this morning, but I managed …….( get ) to school on time. 5. Could you please stop ………….( make ) so much noise ? 6. I’ve put off ………………( write ) the letter so many times. I really must do it today. 7. Sarah gave up ………… ( try ) to find a job in this country and decided…… ( go ) abroad. 8. You can’t stop me …………….( do ) what I want. 9. You must promise…………….( not / be ) late again. 10. Please, don’t forget…………………( post ) the letter for me today ! It’s urgent.

Một ấm điện bằng nhôm có KL 0,5kg chứa 1kg nc ở n độ 20 độ C. Ng ta đổ thêm m(g) nước ở n độ 60 độ C vào ấm thì n độ khi cân = nht là 36,8 độ c. Bt rằng nht dung riêng của nước và nhôm lần lượt là 4200J/Kg.K và 880J/Kg.K ( Bỏ qua phần nht lượng tỏa ra ngoài m trường và coi như phần điện năng chuyển hóa hoàn toàn thành nht lượng) a) Tính KL nước đã đổ thêm vào ấm b) Muốn đun sôi lượng nc trong ấm trên trong 20p thì ấm điện phải có công suất là bnhiu? ( Câu b mong mọi người giải thích kĩ dùm mình nhé , mk chưa hiểu câu b lắm)

Cho 9,6 gam bột kim loại N (hóa trị không đổi) vào 250 ml dung dịch gồm Fe(NO3)2 0,6M và Cu(NO3)2 0,2M rổi khuấy cho đến khi các phản ứng xảy ra hoàn toàn, thu được dung dịch X và 16,4 gam chất rắn Y. a)Xác định kim loại N. b)Tính nồng dộ mol/l của chất tan trong X, coi V dung dịch không thay đổi trong toàn quá trình.

LIFE IN THE PAST VS LIFE IN THE PRESENT Over the last century, there have been many significant changes in the way we live. Obviously, it is difficult to compare the life of ancient people and the life of the people living in the twenty-first century because so many changes have occurred. Even the changes that have occurred over the last ten years are amazing. To start with, in the past people had to work harder as they did not have tools and machines to make their work easier. Today, most of the difficult and dangerous work is done by computers and other powerful machines. In the past living conditions were not as comfortable as they are now. Besides, many people could not afford household appliances like a fridge or a vacuum cleaner because those used to be luxurious goods. Another difference between living now and in the past is the fact that nowadays education is accessible to everyone. In the past men were mainly the only ones educated and women were not allowed into public or private schools. Besides, nowadays it is much easier to find the educational materials and the information you need – thanks to the Internet. We are able to speak to a friend who is on the other corner of the world because we are connected 24/7. Nevertheless, people had better relationships with the neighbors in years gone by. All things considered, it is an obvious conclusion that life has changed significantly during the course of history. In some ways, it is definitely easier to live in the present. On the other hand, however, life now is much faster and stressful than it used to be in the past. The standard of living has definitely improved but it can be discussed whether the quality of our lives is also better. A. Decide whether the following sentences are true (T) or false (F). 1. Life nowadays is the same as life of our ancestors. 2. Technology has made our lives easier. 3. In the past, household appliances were very expensive. 4. Public schools allowed females and males to be educated in the same schools. 5. We can use the internet to communicate with people around the world. B. Answer the questions. 6. Is life today faster or slower than life in the past? 7. What has happened to the standard of living? 8. What makes it easy to access information? 9. Who or what does some difficult jobs for us? 10. What makes our lives easier at home?

Bài 8:Cho A=3x-1/x-1 và B=2x mũ 2+x-1/x+2. a)Tìm x thuộc Z để A,B là số nguyên. b) Tìm x thuộc Z để A,B cùng là số nguyên

giúp em với 5h30 em học rồi bài nào cũng được ạ em đang cần gấp lắm

tính nhanh: 150+90-50=? các bn giúp với

sự khác nhau giữa thể bốn nhiễm và thể tam nhiễm kép e cảm ơn