làm chi tiết k vắn tắt giúp mk với vì mk mới học hóa cảm ơn nhiều

Rút gọn biểu thức (√6+ √14) / (2 √3+ √28) Tính giá trị của biểu thức √ 117 ² - 108 ²

Mở ngoặc âm 5x mũ2đóng ngoặc (2x mũ3-x+1)

Cho hình bình hành ABCD . Trên cạnh AB lấy điểm E , trên cạnh CD lấy điểm F sao cho EF//AD a) CM rằng :AE//DF ; BE//CF b) CM tứ giác AEFD là hình bình hành c) CM tứ giác BEFC là hình bình hành d) AF cắt DE tại M ; BF cắt CE tại N . Chứng minh MN=1/2 AB (quan trọng làm câu d nha, giúp e câu d nhanh vs ak)

1 I wish that the weather ___________ not so cold. A. be B. was C. are D-were 2 I don’t understand this point of grammar. I wish I it better. A. understood B. would be understand C. had understood D. will understand 3 This movie is terrible. I wish we to see another one. A. went B. Would be go C. had gone D. go 4 My father is too busy today. I wish . A. my father is free today B. my father weren’t so busy today C. my father would be busy today D. my father wasn’t so busy today 5 “I’m not staying here any longer.”- “I wish you ” A. can B. will C. are D. were 6 There is no snowing here. I wish it snowing now. A. is B. will be C. were D. was 7 I miss my friends. I Wish they here right now. A. were B. will be C. had been D. are 8 I speak English terriblely. I wish I English as fluently as you. A. spoke B. speak C. had spoken D. will speak 9 My house is too small and old. I wish I a bigger one. A. have B. will have C. had had D. had 10. Sophie wishes her father here now to help her. A. has been B. is being C. is D. were 11 I love California. I wish I go there right now. A. can B. went C. could D. may 12 Iris is always moaning about others. I wish she . A. know how I am upset B. knew how I am upset C. will know how I am upset D. knows how I am upset 13 Stella hates having red hair. She wishes she blonde hair. A. have B. will have C. had D. had had 14 They wish they the exam. A. pass B. passed C. will pass D. are passing 15 Diego is driving too fast. I wish he ___________ more slowly. A. drive B. drove C. were driving D. will drive

Join each pair of sentences to form one sentence. Use the correct word from the list below to join them. and (so) but or because if 1. You don't feel very well. Phone the doctor. → ................................................................................................. 2. You are very ill. The doctor can visit you. → ................................................................................................. 3. I went to see the doctor yesterday. I had a high temperature. → ................................................................................................. 4. He examined me. He gave me some medicine. → ................................................................................................. 5. I've stopped taking the medicine now. The doctor told me to stop. → ................................................................................................. 6. I'm going out. I’m not going to stay outside too long. → ................................................................................................. 7. I’m going to wear warm clothes. I don't want to catch cold again. → ................................................................................................. 8. I took my shoe off. My ankle began to swell and feel painful. → ................................................................................................. 9. Put a handkerchief in cold water. Then place it on your ankle. → ................................................................................................. 10. Bandage your ankle firmly. Don't wrap the bandage too tightly. → .................................................................................................

26. He (take)..................part in the march on May Day at present. 27. My sister (listen).......................to music in her free time. 28. What.................your mother often (do).......................in the evening? - She often (play)....................card but today she (make)...............cake in the kitchen. 29. Poor him! He (not have)........................any money in his pockets. 30. Trang usually (look)..................out of the window while the teacher (teach) ........ 31. Where is your father? - He (be)........................in the bathroom. He (brush).........................his teeth.

Rewrite the following sentences using the words given 1. Mrs Rachel had cleaned my house before I got home yesterday. → I had................................................................................................... 2. My mum told me to go to Australia for further study. sent → I ....................................................................................................... 3. Has Fiona invited you to her birthday party? been → Have .................................................................................................? 4. I didn’t understand a word, so I asked my teacher and she explained it to me. got → I didn’t understand a word, so I ............................................................ it to me. 5. This motorbike is cheaper than I thought I would be. → This motorbike is not............................................................................................. 6. Sue is excited about going to Spain on holiday. forward → Sue................................................................................................................... 7. If you don’t rest, you will be ill. → Unless................................................................................................................. 8. I drank such a lot of coffee that I couldn’t get to sleep. much → I drank so................................................................................................. 9. They couldn’t do anything to stop it. → Nothing ................................................................................................................ 10. She can’t sing as well as she used to. → She used ..............................................................................................................

Cho n là số tự nhiên khác 0 và nhỏ hơn 1000. Tổng các chữ số của số 999.n luôn bằng ……. help, giải thích chi tiết, rõ ràng nha

Hấp thụ hết 3,92 lít khí CO2 (đktc) vào dung dịch chứa x mol NaOH và y mol K2CO3, thu được 150 ml dung dịch X. Cho từ từ đến hết 100 ml dung dịch X vào 200 ml dung dịch HCl 0,5 M, thu được 1,792 lít khí (đktc). Mặt khác cho 50 ml dung dịch X tác dụng với dung dịch Ca(OH)2 dư, thu được 10 gam kết tủa. Hãy tính x và y ?