tìm a để đa thức:2x^3-x^2+4x+a chia hết cho đa thức x+2

Giúp mk 12b và 22a,23b và 24 nhamk cảm ơn lắm luôn

Cùng với sự phát triển của sản xuất và phân công lao động ở buổi đầu thời đại dựng nước Văn Lang, xã hội có những thay đổi ra sao?

20 điểm lun đó trả lời nhanh nha

EXERCISE 3: Choose the underlined part in each sentence (A, B,C, or D ) that needs correcting 1.Debbie, whose father (A) is an excellent tennis player(B), has been (C) playing tennis since (D) ten years. 2. Recently, the island of Hawaii (A) had been (B) the subject of intensive research (C) on the occurrence (D) of earthquakes. 3. Every morning, the sun shines (A) in my bedroom window (B) and waking (C) me up (D). 4. Caroline has worn (A) her new yellow (B) dress only once (C) since she buys (D) it. 5. My friend didn’t drink (A) any (B) beer since we came (C) to live here (D). 6. We have written (A)to each other (B) when (C) we were (D) in primary school 7. What will (A) you do (B) when (C) your friends won’t come (D) ? 8. Someone was knocking (A) at the door (B) when I was doing (C) the washing up (D).

giải phương trình: x^3+(x+1)^3+(x+2)^3=(x+3)^3

Tìm số nguyên X biết: (X+5)+(X-9)=X+2

Mấy bạn làm ơn giúp mình bài này với

EXERCISE 2: Choose the best answer among A, B, C, or D. 1. When I last saw him, he _____ in London. A. has lived B. is living C. was living D. has been living 2. We _______ Dorothy since last Saturday. A. don’t see B. haven’t seen C. didn’t see D. hadn’t seen 3. The train ______ half an hour ago. A. has been leaving B. Left C. has left D. had left 4. Jack ______ the door. A. has just painted B. Paint C. will have painted D. painting 5. My sister ________ for you since yesterday. A. is looking B. was looking C. has been looking D. looked 6. I ______ Texas State University now. A. am attending B. Attend C. was attending D. Attended 7. I _______ in the room right now A. am being B. was being C. have been being D. am 14. I ______ to New York three times this year. A. have been B. Was C. Were D. had been 15. I’ll come and see you before I _______ for the States. A. leave B. will leave C. have left D. am leaving 16. I have never played badminton before. This is the first time I _____ to play. A. try B. Tried C. have tried D. am trying 17. Since _______, I have heard nothing from him. A. he had left B. he left C. he has left D. he was left 18. He will take the dog out for a walk as soon as he ______ dinner. A. finish B. Finishes C. will finish D. finishing 19. He always ________ for a walk in the evening. A. go B. is going C. Goes D. going 20. Her brother ______ in Canada at present. A. working B. Works C. is working D. work

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