GIải giúp mình vớiiii 1. Cho cấp số nhân (un) có u2=3, u3=9. Tìm q và u1 2. Tìm x biết x^2+1, x-2, 1-3x lập thành cấp số cộng

Tính diện tích hình thang có đáy lớn 54m,đáy bé bằng 2/3 đáy lớn và bằng 3/2 chiều cao

Xác định A, B, C, D và hoàn thành các phương trình phản ứng sau: 1. MnO2 + (A) → MnCl2 + (B)↑ + (C) 2. (B) + H2 → (A) 3. (A) + (D) → FeCl2 + H2 4. (B) + (D) → FeCl3 5. (B) + (C) → (A) + HclO

IV. Rewrite sentences by combining two sentences into one sentence and using suggested clues: 1. The air is so dirty. I sneeze so much. CONDITIONAL SENTENCE TYPE 2 - The air was so dirty, I would sneeze so much. 2. Their children have birth defects. The parents were exposed to radiation. BECAUSE - Their children have birth defects because the parents were exposed to radiation. 3. The air pollution causes breathing problems. LEADS ________________________________________________________________________________

Anh chị nào giải giúp em với ạ. Em cảm ơn

Giúp mk câu 5 với mk đang cần gấp nhé

cho a'b là hai số nguyên khác nhau .có thể kết luận rằng m=(a-b)(b-a)là số nguyên âm

Cho 19(g) hỗn hợp Fe và ZnO phản ứng vừa đủ với 500ml dung dịch HCl thu được 1.12l khí H2(đktc). Tính khối lượng mỗi chất trong hỗn hợp ban đầu. tính nồng độ molcuar dung dịch HCl

cho Br2 dư qua 41,45 gam hỗn hợp A gồm NaCl, NaBr,NaI, thu được 36,75 gam hỗn hợp muối B , tiếp tục cho Cl2 dư qua B thu được 23,4 gam hỗn hợp muối C. tính % khối lượng muối NaBr trong A

1. Oil, coal and natural gas are ............. fuels made from decayed material from animal or plants. a. unleaded b. smokeless c. solid d. fossil 2. We could make better ............ of our energy resources. a. spend b. use c. need d. limit 3. The government has spent 1 million on an advertising ............. to encourage energy conservation. a. campaign b. promotion c. operation d. enterprise 4. Many newer cars have a much lower fuel ................ a. consuming b. consumer c. consumation d. comsumption 5. Completed in 1756, Nassau Hall is the oldest building now ............. on the campus of Princeton University. a. standing b. it stands c. has stood d. stood 6. The Massachusetts State House, ............... in 1798, was the most distinguished building in the United States at that time. a. completing b. which was completed c. was completed d. to be completed 7. Norman Weiner, ............... mathematician and logician, had an important role in the development of the computer. a. who as a b. was a c. whom a d. a 8. War and Peace, ............... , was published in 1869. a. Leo Tolstoy's most celebrated novel b. that Leo Tolstoy's most celebrated novel c. which most celebrated novel of Leo Tolstoy d. is a Leo Tolstoy's most celebrated novel