1)Xác định m và n để các phương trình sau đây là phương trình bậc hai a) (m-2).x^3+3.(n^2-4n+m).x^2-4x+7=0 b) (m^2-1).x^3.(m^2-4m+3).x^2-3x+2=0

Giúp em nội dung và ý nghĩa vơi ạ

Em đang cần gấp. Các bạn giúp em với ạ

Cho m(g) hỗn hợp X (Al, Mg) tác dụng hoàn toàn dd HCl, kết thúc phản ứng thu được 5,32 lít khí H2(đktc) và dd Y, khối lượng dd Y tăng 3,94g. Tính mAl trong X Mng giúp mình với nhé

một khoáng vật có thành phần về khối lượng là: 13,77%Na;7,18%Mg;57,48%O,2,39%H và còn lại là 1 nguyên tố khác . Xã định công thức hóa học của khoáng sản

GIÚP MÌNH VỚI V. Circle the best answer to complete the sentences 1. She (teached/taught) Vietnamese and Maths for the handecapped children when she was at university. 2. They (begin/began/begun) his volunteer work about five years ago and they (finded/found) it useful and meaningful as it (could/can) bring some change for community. 3. We (think/thought) that only donating money could help the poor and the disadvantaged, but in fact, we can do more to help them now. 4. The boys accidentally (broke/breaked) the Brown’s window while they (player/were playing) baseball. 5. They ( built/was building) a bridge to help the local children go to school easily when they visited their village where they ( were/are) born. 6. Yesterday, after his farewell with his girl friend, he ( drunk/ drank) a lot, so I (take/ took) a taxi for him. X. Write sentences using the word below, do any changes if necessary 1. Do/ volunteer work/much mean. 2. I/go/zoo/girl friend/yesterday morning. 3. We/stop/petrol station/car/ran/petrol. 4. She/play/guitar/8 p.m/yesterday evening. 5. She/accident/cut/herself/while she/shop/chicken. 6. I/walk/home/school/when/it/sudden/rain/heavy. 7. Play/game/interest/him/so bore/use/me. 8. couple/walk/park/when they/see / big rat.

Tìm n biết: a) 3 chia hết cho n+5 b)-3n+2 chia hết cho 2n+1

Viết lại câu theo dạng bị động 1) People play football ever the world - Football ............................... 2) They were cleaning the room when I arrived - The room................................... 3) We have not finished our homework yet - Our homework....................................... 4) We must write to him - He ............................................. 5) It is two months since I saw her - I have not........................................ 6) We last went to Sa Pa two years ago - We have not ...................................... 7) He has never played a computer game - This is ........................................ 8) We have not seen her since we lelf universaty - The last time............................. 9) Quan does not type as fast as she used to - Tam used .................................. 10) How long is it since you used the car - When .......................................

Giúp mk câu 1b,1c và câu 2b với ạ mk cảm ơn trước

Ai giúp mình làm với ạ xin cảm ơn nhiều