Cho hình thang cận ABCD (AB//CD,AB <CD) Gọi O là giao điểm của AD và BC. Gọi E là giao điểm của AD và BD. Chứng minh a. Tam giác AOB cân tại O b. Tam giác ABD bằng tam giác BAC c. EC=ED d. OE là đường trung trực của AB và CD

cho x+y+z=3 và z^2+y^2+z^2=9 tính giá trị p =(yz/x^2+xz/y^2+xy/y^2-4)^2019

2. When Lan wad small, she used to cry a lot Lan often c 3. I walk to school in 20 minutes every day It takes 4. last week, she spent two days tidying the room It took 5. I have started learning English in 200 It began raining haft an hour ago 6. William is too fat to wear this jean William 7. Her car is more comfortable than mine. Her 8. I have 5 book, he has 10. I ( use fewer) 9. I can drink 2 can of bear, he can drink 3 cans He ( use more) 10. My favourite subject is English I 11. He enjoy studying Maths He is in frond of 12. Let’s go our for drink Why 13. How much does her dress cost? How much 14. what was the price of these shoes? How much 15. Why do not ask your teacher’s help” she ask me She advised 16. She is very poor. She cannot buy a book She is so 17. he is better than his father This father 18. I regret not meeting him earlier I wish 19. He fail the exam because he did not study hard. If 20. I have never met a more beautiful woman than her She 21. the last time I met her was when I was in Hue city. I haven’t 22. She said “ Nam , I will give your mother a gift” She promised 23. I finish the test in one hour. I took 24. “Remember to lock the door” Tims’s father said Tim’s father reminded 25. the man tried to escape but the police stopped him. The police prevented 26. Tuan is my boyfriend, his father is a doctor Tuan 27. The girl is a singer. We met her at the party. The girl 28. The bananas are on the table. George bought them. => The bananas 29. I have to learn new words. They are very difficult. => The new words 30. it is not necessary for you to do the exercise today. You do not

1. tam giác ABC vuông tại A có đường cao AH HB=1 HC=3 tính cosin B 2. biết sin anpha = 3/4 vậy cosin anpha = bao nhiêu

vai trò của nhà cửa đối với đời sống con người

Tìm x (X-1/4)^3=-1/125 (x-1/5)^3=-1/27

Giúp em với ạ chiwuef em đi học ruii, cảm ơn mn ạaa

Nhà cử sạch sẽ ngăn nắp có tác dụng gì? Vì sao phải dọn dẹp nhà của thường xuyên

so sánh sự giống và khác nhau của khu vực Châu Phi và khu vực Mỹ La Tinh?

giúp mk vs T^T 3 thi r bài hình nhoa