Chứng minh BĐT Cosi cho 2 số thực không âm

x+1 / 4 + x+2 / 2003 = x+3 / 2002 + x+4 / 2001 Mong các bạn giúp đỡ mình ạ

Câu 1, 2 nha mọi người cả hai càng ok

Ngoài cảnh vườn bách thú "tầm thường, giả dối và tù túng "dưới mắt con hổ tác giả muốn nói tới điều gì

Rewrite the sentence : Does your sister travel to work by bus every morning? Your sister..........................?

Thái độ của bé Thu với anh Sáu có sự thay đổi trong lần gặp mặt đầu tiên và lúc chia tay. Em hãy chỉ rõ những thay đổi đó và lí giải nguyên nhân.

Giúp mình bài này với ạ?!!!!!!!!

Một người viễn thị nhìn rõ vật bắt đầu từ khoảng cách d1 = 100/3 cm khi không dùng kính còn khi dùng kính nhìn rõ vật bắt đầu từ khoảng cách d2 = 25 cm. Độ tụ của kính người đó đeo là Giup minh voi ak. thank

Bạn An đọc một cuốn sách trong 3 ngày. Ngày thứ nhất đọc 1/3 số trang . Ngày thứ hai đọc 5/8số trang còn lại. Ngày thứ ba đọc nốt 24 trang. Tính xem cuốn sách đó có bao nhiêu trang?

II. Read the dialogue, then choose the correct answers.(2,5ms) Marie: We might go to the football match next Saturday, Cristina. Cristina: Football? You must be joking. I can’t stand it. Mark: No? Why not? Cristina: Twenty two men of two teams run after a ball, trying to kick it into a net... and thousands of people shouting and screaming like madmen every time it’s a goal or not. Is this a game? Mark: I see... you prefer things like hopscotch, hide-and-seek, blind man’s buff... Cristina: Don’t tease me, Mark. I’m not a child anymore and there are much better sports than football. Mark: Really? Cristina: Yes, take volleyball, for example. It’s so exciting, the two teams try to keep the ball in motion without letting it touch the ground. No foul play, no violence. Mark: Yes, maybe you’re right I like volleyball too. For me all ball games are great! Cristina: Not only ball games, Mark. Don’t you like badminton, cards, chess, even darts...and things like that? Mark: Er...of course I do. 1. What are Cristina and Mark talking about? a. Football b. Volleyball c. Ball games d. Games 2. How many football players are there in each team? a. 11 b. 12 c. 20 d. 22 3. Why does Mark mention children’s games like hopscotch? a. Because Cristina likes these games. b. Because Cristina is a child. c. Because he wants to tease Cristina. d. Because he wants Cristina to play these games. 4. What kind of sports and games does Cristina NOT refer? a. Chess b. Baseball c. Badminton d. Darts 5. Cristina thinks football is an exciting game. a. True b. False c. No information Task 3. Complete the passage with the words from the box. (3,5ms) score sport without positions boring play has Basketball is a pretty cheap (1)______________ to play in terms of equipment. So long as you have shoes and clothes and a ball, you can play. You can play with 1 hoop or 2, but it is way more fun to have a full court to (2)___________ on and several friends to do it with. Of course, you can have knee braces, expensive shoes, and some fancy jerseys if you want, but you can play (3)___________ them if you want. Basketball is a game of 5-on-5. There are 5 different (4)___________: point guard, shooting guard, center, small forward, and power forward. Unlike some other sports, all players can (5)___________ points, and there is NO goalkeeper. There isn’t a (6)________________position to play! Basketball (7)__________________ 4 quarters. For pro games, quarters are 15 minutes. Teams switch directions of play after each quarter.