Chứng minh biểu thức luôn dương với mọi giá trị của biến

A/ -4/9+1/3 -(-5/6) B/ -7/12 -(-14/15)+(-5/6) C/ 2/3-[(-7/4-(1/2+3/8)]

Thêm bớt để tính giá trị biểu thức 1. a^4+4 2) a^4b^4+324 3) a^4b^8 + 64c^4

Nếu có thể thì vẽ giùm mình hình ạ. Mình xin cảm ơn. Cho hình chữ nhật ABCD có O là giao điểm 2 đường chéo. Trên OB lấy điểm I bất kì. Gọi E là điểm đối xứng của A qua I và J là trung điểm của CE. Đường thẳng IJ cắt BC tại F và cắt đường thẳng CD tại H. 1) Chứng minh : OIEC là hình thang. 2) Chứng minh : OIJC là hình bình hành. 3) Chứng minh : ΔJCE cân. 4) Chứng minh : EFCH là hình chữ nhật.

8. When tourist come to a specific place, many of them choose to buy crafts as souvenirs to ____ them of the place they have been to. (REMIND) 9. These _____ live mainly on farming and marking incenses when crops are over. (VILLAGE) 10. The place has a rich long - lasting ____ (HISTORY) Exercise 3: 1. These baskets are ______ from strips of bamboo. (WEAVE) 2. We are impressed by a wide _____ of lacquerwares in the showroom. (VARY) 3. My grandfather has devoted himself to many _____ events in our community. (CULTURE) 4. Do you know that ____ have to follow 15 stages to make a conical hat? (ART) 5. There are a lot of silk _____ such as scarves, ties and dresses in our shop. (PRODUCE) 6. They showed me a marble sculpture which was _____ made by hand. (SKILL) 7. Obviously, our handicrafts are in _____ with those of other villages. (COMPETE) Exercise 4: Some people ask me if I like living in my hometown. The answer is certainly ‘yes’. The simple reason is that it has lots of (1. interest) .............................. places. If you want to widen your knowledge of the past, you can go to the museum. It’s a (2. history).............................. building, with a big collection of valuable artefacts. There is also a craft village in my hometown. There, the (3. village) .............................. make drums. Their drums are not only famous in the (4. local) .............................. level, but also nationwide. You can visit the old workshop, where drums are still made in the traditional way. Some of them are huge! Another (5. attract) .............................. in my hometown is the local library. It’s an (6. educate) .............................. place where anyone can borrow books and take them home to read. Besides, it also has a (7. read).............................. club. I’m one of its members, and we gather once a week to discuss what we’ve read together. My hometown is also a (8. culture) .............................. centre, with many traditional festivals and activities. I love it very much. làm vầy nè:Search danh từ tính rừ trạng từ,.. Của từ + nghĩa

Tìm các cạnh của hình chữ nhật biết tỉ số giữa hai cạnh là \frac{2}{3} và chu vi của hình chữ nhật là 60m.

xác định các thành phần của câu , cho biết chúng thuộc kiểu câu gì ? a. uống nước nhớ nguồn . b. ngoài khơi xa , những cách buồm nâu thấp thoáng . c. ồ ! chiếc áo này hơi dài . d. chúng hạn chế mở trường học

Tìm x: a) 3x^2 + 10x + 3=0 b) 6x^2+20x+6= 0

403. The main ……… of the book was the predictable ending. (WEAK ). 404. We had a marvellous holiday and our trip to the moutain was ….. . (FORGET ). 405. She got very angry but later she opologized for her ……. . (PATIENT ). 406. It was extremely ………. of you to leave your library books on the bus .<CARE ). 407. To win the gold medal you have to beat all the ……… . (COMPETE ). 408. Some parents worry about their children’s …… to computer games. (ADDICT ). 409. I had my trousers …….. because they were too short . (LONG ). 410. UFO means …………… Flying Object. (IDENTIFY ).

giúp e với, 11h e nộp bài. Tkss 4. People like to live in this country because of its healthy climate. Because 5. Our leader couldn't attend the meeting, so it was canceled. Because 6. Harry had to stay in hospital because of his broken leg. Because 7. Because of bad driving conditions, we postponed our trip. Because 8. John has to sit in the front row in class because he has poor eyesight. Because of