rút gọn biểu thức M=((2/x*y)/((1/x)-(1/y)))-((2*x+2*y)/(x-y)^2)

Tìm số nguyên a để phân số sau cũng là số nguyên: -14 a - 9

Câu 3b: khí clo là khí mùi xốc,rất độc,có khả năng phá hoại niêm mạc của đường hô hấp.Trong phòng thí nghiệm,người ta điều chế và thu khí clo bằng phương pháp dời chỗ không khí theo hình vẽ sau: -Nêu phương pháp an toàn và đơn giản để nhận biết khi nào bình (3) đã thu đầy khí clo Giúp mình câu 2 và câu 3b với ạ

Các bạn giúp mình vs nhé bài này khó quá mình klđ

Giải cứu e với e ko làm xong thì tiêu e luôn

Giải giúp mình câu này với (x+7)-(24+35)

Giúp mình mấy câu trắc nghiệm này vớiii

I - Choose the word A, B, C or D whose underlined part is pronounced differently from the othe 1. A. rubbish B. uniform C. umbrella D. thumb 2. A. appear B. weather C. bread D. headache 3. A. project B. belong C. woman D. concert 4. A. think B. though C. mother D. these 5. A. eraser B. baseball C. suitcase D. waterfall

tìm x biết: [x] bé hơn hặc = 3

VII. Chia động từ 1. John ................... reading. (not, like) 2. ................... any of you ................... sports regularly? (play) 3. I rarely ................... newspapers. (read) 4. Yesterday I ................... you talking to a stranger. (see) 5. Tonight we ................... to the opera. (go) 6. Right now he ................... on the phone. (talk). 7. You are late, the lesson ................... fifteen minutes ago. (start) 8. When ................... the Beatles ................... their first album? (record) 9. On Friday I ................... to the boss about a rise. (talk) 10. These days we ................... a lot. (work) 11. My father ................... Maths at a secondary school. (teach) 12. I ................... any book now. (not, read) 13. ................... you ................... anything yesterday? (buy) 14. When I ................... (go) home, I ................... (meet) John. 15. At this moment he should ................... his final exam. (write) 16. Jane ................... to Washington tomorrow. (fly) 17. Don't disturb me while I ................... (work). 18. Holidays ................... last Friday. (begin) 19. At midnight I ................... still ................... home. (drive) 20. Every Sunday we ................... to church. (go) 21. When I ................... (wake up), the sun ................... (shine) and the birds ................... (sing). 22. Look, the sun ................... (set) 23. In summer the sun ................... about nine o'clock PM. (set) 24. While I ................... (sleep), he ................... (clean) the house and ................... (prepare) dinner. 25. What ................... you ................... yesterday at 11 AM? (do) 26. I ................... never ................... to Australia. (be) 27. ................... you already ................... your car? (wash) 28. He ................... just ................... back. (come) 29. She ................... not yet ................... doing her homework. (finish) 30. I ...................(love) her since I ................... (see) her for the first time. 31. A strange thing ................... (happen) while I ................... a letter. (write) 32. John ................... his garden every two days. (water) 33. We ................... each other for ten years. (know) 34. My grandfather ................... all those trees before the war. (plant) 35. As I ................... dishes (wash), the phone ................... (ring) 36. Be quiet, I ................... to concentrate. (try) 37. Jane ................... many books about Chinese culture. (write) 38. She ................... her first book in 1990. (write). 39. She ................... currently ................... a book about Chinese painting. (write) 40. My parents ................... married 20 years ago. (get) 41. My best friend ................... married next Saturday. (get) 42. We ................... (watch) a football match on the TV when the electricity ..................out. (go) 43. Last night he ................... back at 2 o'clock. (come) 44. It ................... all night. (rain) 45. Somebody ................... (knock) on the door. - I ................... (open)!