Cho thấu kính hội tụ, ti u cự f = 15 cm. V t s ng AB = 2,5 cm đặt vuông góc v i trục chính, A tr n trục chính và c ch thấu kính 7,5 cm. Hãy x c định vị trí, tính chất, chiều cao c a ảnh A’B’ cho bởi thấu kính?

giải hộ mình vs ạ vote bạn nào nhanh nhất ạ

x/3 - 1/2 =1/5 Tìm x hôk mình với ạ!

giúp mình với ạ hứa vote 5 sao

1. Lập phương trình hóa học của các phản ứng có sơ đồ sau: a. Ag + O2 Ag2O b. Fe + HCl FeCl2 + H2 c. Al + FeCl2 AlCl3 + Fe d. Mg + AlCl3 MgCl2 + Al e. Al + HCl AlCl3 + H2 f. P2O5 + H2O H3PO4 g. N2O5 + H2O HNO3

II. Choose the correct answer: 1. He said he……………..at the “Ritz” Hotel. A.is staying B. has stayed C. was staying D. will stay 2. He asked me where I……………. A. have studied B. study C. am studying D. studied 3. Tina asked me how long I……………..a teacher. A. have been B. had been C. am D. will be 4. She asked me…………….I liked pop music. A. if B. whether C. that D. A&B 5. The students asked if I was going to teach them physics……………… A. the next day B. next day C. day next D. the day next 6. John asked me _______ in English. A. what does this word mean B. what that word means C. what did this word mean D. what that word meant 7. She said I _______ an angel. A. am B. was C. were D. have been 8. Laura said she had worked on the assignment since _______. A. yesterday B. two days ago C. the day before D. the next day 9. John asked me _______ interested in any kind of sports. A. if I were B. if were I C. if was I D. if I was 10. John asked me _______ that film the night before. A. that I saw B. had I seen C. if I had seen D. if had I seen 11. “Go home,” said the teacher to us. A. The teacher told us to go home B. The teacher said us to go home C. The teacher told us go home D. The teacher told to us to go home 12. “Please bring me some fish soup,” he said to the waitress. A. He asked the waitress bring him some fish soup. B. He asked the waitress to bring her some fish soup. C. He asked the waitress to bring him some fish soup. D. He asked the waitress bring her some fish soup. 13. I said to Nick: “Where are you going?” A. I asked Nick where was he going. B. I asked Nick where he was going. C. I asked Nick where is he going. D. I asked Nick where he is going. 14. “You’d better apologise for being late,” said my mother. A. My mother advised me to apologise for being late. B. My mother suggested me to apologise for being late. C. My mother suggested apologising for being late. D. My mother warned me to apologise for being late. 15. “Don’t open your books,” the teacher said to the pupils. A. The teacher told the pupils to not open their books. B. The teacher told the pupils did not open their books. C. The teacher told the pupils not open their books. D. The teacher told the pupils not to open their books.

Moi nguoi lam on giup minh voi a

Tìm x 1)x^3-3x^2+4=0 2)x^4+x^3-4x^2-5x-3=0

xác định từ loại trong các từ của các câu A)nước chảy đá mòn B)dân giàu nước mạnh

Tính thể tích dd Ba(OH)2 0,04M cần cho vào 100ml dd gồm HNO3 0,1M và HCl 0,06 M có để pH của dd thu đựơc = 2,0.