Công thức hóa học của hợp chất tạo bởi nguyên tố X với oxi là XO, của nguyên tố Y với nhóm hiđroxit (OH) là Y(OH)3 . Công thức hóa học của hợp chất tạo bởi nguyên tố X với nguyên tố Y là A:X3 Y2 . B:XY3 . C:X2 Y3 . D:X3 Y.

1) CM hai số sau nguyên tố cùng nhau: a)2x+1 và 6x+5 b)2x+3 và 4x+8 2)tìm x thuộc Z biết: a)x+4 chia hết cho x+1 mong mn giúp e ạ câu nào cũng được ạ

Trong bài thơ "Khi con tu hú" của Tố Hữu , tiếng chim tu hú xuất hiện mấy lần? Hãy chỉ ra ý nghĩa , giá trị liên tưởng mà âm thanh của tiếng tu hú gợi lên

Giải bất phương trình giúp mình với bạn. Cảm ơn rất nhiều.

làm sao để = 115x giúp mình vs nhé

Ai giỏi tiếng anh giúp mình ik mình cảm mơn 😘😘

Cho tam giác ABC cân (AB=AC). Trên cạnh AB lấy điểm D, trên cạnh AC lấy điểm E sao cho : AD = AE . a) Chứng minh BE = CD. b) Chứng minh: ∠ABE=∠ACD c) Gọi K là giao điểm của BE và CD. Tam giác KBC là tam giác gì? Vì sao?

Bài 24: chứng minh A B Bài 25: chứng minh A B

1.My father goes to work by driving……………. A. horse B. bicycle C. motorbike D. car 2.My English teacher, Mr.Nam, often drives his car…………..on the way to school. A. careful B. caring C. carefully D. careless 3.We must obey traffic rules……………our safe. A. to B. for C. on D. of 4. When I was at primary school. My father ………….to school every day. A. takes B. is taking C.used to take D. is used to take 5. John is a pilot . He …………………on airplanes. A. used to fly B. uses to fly C. is used to flying D. used to flying 6. There ………….a stadium in the town but now there isn’t . A.use to be B.was used to C. is used to D. used to be 7. Did you ………………to the cinema when you lived inLondon ? A. used to go B. were used to go C. use to go D. were used to going 8. Why didn’t you ……………..the bus I told you ? – Because I changed my route. A.catch B. get C. give D. go 9. If you do not have ………….., you will not able to drive on the road. A. helmet B. driving license C. mask D.warm clothes 10. Passenger are going to …............the airplane. A. get off B. take off C.turn off D. go off 11. There is a love story in it, and it is very funny. I suppose you call it a………………………… A. horror film B. action film C. romantic comedy D. thriller 12. Mr Lam often finds his job ………………….. . A. exhaust B. exhausting C. exhausted D. exhaustedly 13. The person who tells the actors and actresses what to do ……………. A.manager B. character C. actor D. director 14. The people who watch a film called ……………….. A. characters B. audiences C. actors D. film makers 15. I love travel by …………………..I can see the whole city from above the sky . A. bus B.boat C. train D. airplane 16. Be careful or you will fall…………your bicycle. A. off B. of C. in D. on 17. A film that presents actual event is called a….…………. . A. horror B. thriller C. comedy D. documentary 18. The film is too …………….to show to children. A. violence B. violent C. violently D. interested 19. The movie was so …………..,that we couldn’t sleep at night . A. thrill B. thrilling C. thrilled D. thriller 20. I couldn’t take my eyes off the …...............because the film was so interesting. A. actor B. picture C. poster D. screen III/ Write the correct form or tense of verbs in brackets. 1…………………………(you / ever/ drive) on the wrong side of the road? 2.My family ……………………….( fly ) back from our Hong Kong holiday two days ago. 3.Right now, the students……………………………( learn) road signs in the schoolyard. 4. Usually Oanh ……………………( walk) to school, but this week she (ride)…………….her bike. 5. The driver was so drunk that he ……………………….….(lose) control of his car. 6.If I have enough money, I ……………………………(buy) a racing car. 7. My father ……………………………(teach) me to ride a bike when I was seven. 8.Transport used ……………………………(be) much slower three hundred years ago. 9. Saudi women weren’t allowed ………………………………( drive ) a car until recently. 10.In South Africa, you have to let animals……………………………….(go) first.

Cho tam giác ABC vuông tại A, có AB=5cm, AC=8cm tính BC theo định lý py-ta-go