một thửa ruộng hình thang có đáy lớn là 55m và đáy nhỏ bằng 3/5 đáy lớn,chiều cao bằng trung bình cộng 2 đáy . b)biết rằng cứ 100 mét vuông thì thu hoạch được 65 kg thóc .Hỏi trên thửa ruộng đó người ta thu được bao nhiêu tạ thóc ?Bao nhiêu tấn thóc

tìm các cặp số nguyên x,y biết 5xy+5x+2y=-16

IV. Each sentence has One mistake. Find and correct it: (10 points) 1. Huong spent half an hour to tidy the bathroom. 2. Peter is getting used to eat with chopsticks. 3. I don’t know where my pen is. I’ve looked at it everywhere. 4. We last saw a cowboy movie since we were in the city. 5. The man sang English songs beautifully is my elder brother. 6. He asked me why I don’t like playing computer games. 7. The story wasn’t short enough for me to read it in one day. 8. She finds it interestingly to do the housework. 9. I would rather you not go to school by motorbike. 10. These people are always made work very hard on the farm.

Vote cho 5 sao nè Giải các phương trình sau : a)(10x-5)/18+(x+3)/12=(7x+3)/6-(12-x)/9 b)(x+4)/5-x-5=(x+3)/2-(x-2)/2

chứng minh đẳng thức sau với a,b,c ∈Z a) a ( b + c) - b ( a - c ) = ( a + b ) c b) a ( b -c ) - a ( b + d)= -a ( c + d ) = -a ( c + d ) c) ( a + b ) ( a -b ) = a ^ 2 - b ^ 2 d) ( a + b ) ^ 2 = a ^ 2 + 2ab + b^2 e) ( a - b ) ^ 2 = a ^ 2 - 2ab + b^2

Tìm GTNN của G=ab+bc+ca với a^2+b^2+c^2=1

III. Supply the correct form of the words in the brackets: (10 points) 1. He is laughing ________because he has just got a bad mark. HAPPY 2. Life in the countryside is more ________now. COMFORT 3. Mai is taking part in a flower - ________contest next weekend. ARRANGE 4. Tet holiday is one of the most important ________ for Vietnamese people. CELEBRATE 5. I couldn’t make friends with him because he is ________ . FRIEND 6. My house is on the top of a hill, so it is ________in the fall. WIND 7. Picasso is a famous ________. His pictures are invaluable. ART 8. Their children have quite _________ characters. DIFFERENCE 9. There are three ________ in the rice – cooking festival. COMPETE 10. They can measure the ________ of this well. DEEP

Làm hộ em với ạ! Em cảm ơn!

Một viên đạn khoi lượng 50 g đang bay ngang với vận tốc không đối 200 m/s tới đâm xuyên vào một tấm gỏ. Viên đạn xuyên qua tấm gỗ chỉ dày 2 cm và bay ra ngoài. a. Xác định lực cản trung bình của tấm gỏ tác dụng lên viên đạn? b. Vận tốc của viên đạn khi nó vừa bay ra khỏi tấm gỗ? ( Coi lực cản trung bình của gỗ là ng đối )

I. Choose the word that has underlined part pronounced differently from others: (5 points) 1. A. cups B. roofs C. banks D. doors 2. A. honor B. buddhist C. house D. hour 3. A. teacher B. machine C. kitchen D. beach 4. A. cooked B. weighed C. laughed D. coughed 5. A. parents B. apple C. character D. glass II. Choose the best answer to complete each sentence: (10 points) 1. Ba said that he __________ Hoi An the following vacation. A. visit B. visited C. would visit D. will visit 2. Our school is too old. It _________ next year. A. is rebuilding B. is rebuilt C. will be rebuilt D. will rebuild 3. I am attending a class _________ by a famous teacher tomorrow. A. given B. will give C. is given D. giving 4. Thanks ________ Alexander Graham Bell’s invention, we can communicate with each other easily. A. for B. from C. on D. to 5. The children felt __________ when their mother came home. A. exciting B. excitingly C. excited D. excitedly 6. Lan _________ coins and stamps since she was six. A. was collecting B. has collected C. collected D. have collected 7. Could you do me a favour, please?. ~ __________ . A. Certainly B. What for? C. Let’s do D. You’re welcome 8. “_________ bad weather we are having this summer!”; said the old man. A. What a B. What C. How a D. How 9. I am having my father _________ a new shirt for me. A. designed B. designs C. to design D. design 10. Tuan would prefer __________ soccer rather than watch it on TV. A. to play B. playing C. play D. being played