50*4+50*3+50*2 +50 có nhóm nào hốt tôi ko

Trộn 200ml HNO3 0,15M với 300ml đ NaOH phản ứng vừa đủ. Tính CM của các chất có trong dung dịch sau phản ứng(coi V ko đổi)

The teacher let the students leave earlier( Viết lại dưới dạng passive voice và cho biết đây là thì gì?) =>The students.....

Giải giúp e bài 7 hoặc bài 8 ik ạ

1. Where you (be)? - I (be) to the dentist. 2. You (have) breakfast? 3. He just (go) out. 4. You (hear) from her lately? 5. How long you (Know) Mr Pitt? - I (know) him for ten years. 6. He (post) the letter? 7. Why he (not finish)? He (have) plenty of time. 8. I (not pay) the telephone bill yet. 9. I (ask) him to dinner for several times. 10. My parents (buy) a new house recently câu2: 1. How long you (live) here? – I (live) here since 1970. 2. He (live) in Paris for two years and then (go) to EDINBURGH. 3. You (wear) your hair long when you were aat school. 4. But when I (leave) school I (cut) my hair and (wear) it short ever since. 5. My brother (write) several plays. He just (finish) his second tragedy. 6. He (not smoke) for over five years. 7. When you (begin) school? – I (begin) school when I (be) five. I (go) to a primary school first. I (stay) there for six years and then I (go) to a comprehensive school. 8. How long you (work) for Johns and Company? – I (work) for them for two years. 9. I (buy) a new house last year, but I (not sell) my old house yet, so at the moment I have two houses. 10. Ann (go) to Canada six months ago. She (work) in Canada for a while and then (go) to the United States.

(1-x)*(1+x+x^2) Giúp! em cảm ơn nhiều ạ

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Tìm GTNN của biểu thức : A= $a^{4}$ - $2a^{3}$ - 4a+5

Thu gọn rồi tìm nghiệm của đa thức sau: f(x) = x(1-2x) + ( $2x^{2}$ -x + 4)

giải giúp e giải bài tập tiếng anh