Chứng minh rằng a+b+c=0 <=> a^3+b^3+c^3=3abc

Tại sao tôi cảm thấy học ở trên này cực kì khó chịu ? Mọi người trong này như những con hổ đói ? Vậy trang học tạp này để làm gì ? Là nơi để hoidap đúng nghĩa hay là nơi chỉ để cho những con người không xứng đáng to .. mồm ? Rất bức xúc về những con người trên đây ... Vẽ hộ anime tức giận

Câu này sai chỗ nào và sửa lại ra sao nhỉ cả nhà ơi Machinery has made farm production easily and has liberated labor work

Thay các chữ bằng chữ số thích hợp: a, ab x ab = acc b, 1abc x 2 = abc8

Có bđt nào : `ab ≤{a^2+b^2}/2` không ạ *Nếu có thì cho bài tập dạng này giúp ạ

Bài 4: Nổi 2 câu don dã cho thành câu ghép, sửr dụng liên từ thích hợp. lim was absent from class yesterday He was suffering from a bab cold. be cause 3 They decided to move the house jlhey don't have to travel a long distance to work. 3 Mary heard her fingers yesterday.She was reparing dinner. 4. At 4 pm yesterday, my mother was cleaning the house. I was looking after my younger brother. 5. They decided to go on an excursion. They want to get away from work stress. 6.My father taught me how to use the computer. Before that, I didn't know how to use 7.1 arrive at the station. I will call you right after. 8. My brother is very out-going. I am quiet reserved. 9.Mr Peter was walking home.He was robbed of his wallet. 10.I don't have a pet. My mother doesn't allow me to have one.

Câu 1 : Thực hiện phép tính (tính nhanh nếu có) a) 2013⁰ × 19 + 99 × 19 - (2³ : 2² + 3³ : 3) Câu 2 : a) 300 : (x + 3)² - 3 = 0

cho hình hộp chữ nhật ABCD.A’B’C’D’ có A’A=2a , ((A’BC),(ABCD))= 60° và (A’C, (ABCD)= 30°. Tính theo a thể tích khối hợp chữ nhật

Ai giỏi hình giải giúp với ạaaaaaaa Cho ∆ABC vuông tại B. Biết BC = 15cm, BA = 8cm, trên cạnh BC lấy điểm E sao cho BE = BA. a) Tính AC b) ∆ ABE là ∆ gì? Vì sao ( cái này giải y như chứng minh luôn nha ) c) Từ B kẻ đường thẳng vuông góc với AE tại H và cách AC tại D. Cm : BD là tia phân giác góc ABC d) Gọi I là giao điểm của của AB và DE. Cm : AE // IC.

Write the word the, where it is appropriate in the text, in the places indicated. (1)-------- 6.45 train, which went from Winchester to Southampton, was already full of (2) ------------commuters when Rale boarded it with fifteen minutes to go before its departure. He registered (3) ---------vague annoyance at this, as it meant he had to actually communicate with a fellow passenger in order to find (4) one remaining window seat in his normal carriage, (5) ---------carriage C. Rale always made a point of travelling in the middle carriage for (6)---------- safety's sake - about such things as (7)---------- safety he was meticulous - and would only venture into (8) first four carriages, or for that matter (9) last four, in (10) extreme emergencies. Rale was nothing if not a creature of (11) habit; it bothered him intensely if he was unable to get a window seat or if (12) drinks trolley lady didn't come round, or worse still, she came but (13) hot water boiler wasn't working and so (14) coffee was not available. A brioche and a cup of coffee - black, one sugar - was Rale's early-morning indulgence. He found it sufficed for a breakfast, unless he was unusually hungry. Exactly ten minutes into (15) journey, Rale opened his briefcase and took out his copy of that morning's Guardian newspaper, neatly folded, and began (16) crossword. This was (17) time of day Rale liked best. He could immerse himself in (18) delightful challenge of teasing out words from his mind, and put off (19) thoughts of work in the administrative department of (20) Southampton Hospital. Today, however, Rale's neatly planned existence was to be well and truly turned on its head.