chúng minh rằng: a^3 - b^3 = (a - b)^3 + 3ab(a - b).Chứng minh vế trái giúp mình nhé

cân bằng pt KMnO4 + HCl -> KCl + MnCl2 + Cl2 + H2O giúp với

VII/ (1,5p) Complete the following sentences, using the words or phrases suggested. I / feel / hopeful / that / we / find / suitable house / very soon. She / not / play / piano / well / as / her sister. I wish / could / give you / all the expensive things / life. You / hear / Maria / since / you / leave school? The people / live / next door to us/ keep / have / all night parties. VIII/(1,5p) Finish each of the following sentences in such a way that it means exactly the same as the sentence printed before it. People are going to build a new library in the area. A new library _______________________________________________. “Why don’t you take a day off tomorrow?” she said to me. She suggested that ____________________________________________. The weather is bad so we can’t go camping. If the weather ________________________________________________. He was punished because he behaved badly. Because of __________________________________________________. The keeper had no sooner opened the case door than the lion attacked him. à=Hardly ______________________________________________________.

Complete the funny story with the Past Simple of the verbs in brackets It (1.be)______ Sunday, the day of the big game. The players (2.arrive)_____ early. They (3.be)_______ excited. Everyone (4.want)_____to play. There (5.be)______ lots of people stadium. They (6.wave)____ and(7.cheer)____ when the players (8.walk)______on to the ground. There referee(9.call)____ the captains to the middle. The referee (10.ask)______.:"Where is the ball?"Nobody (11.answer)______. All the players (12.look) at the ground. There (13.be)______ no ball. The referee (14.cacel)____the game

một bể nước cao 1,5m , đáy là hình chữ nhật có chu vi 7,2m , chiều dài hơn chiều rộng 0,6 m. a) hỏi bể nước đó chứa được bao nhiêu lít nước ( 1 dm ³ - 1l) b) biết rằng sau 1 tuần lễ dùng nước , mực nước trong bể giảm đí,2 m. tính trung bình mỗi ngày dùng bao nhiêu lít nước

Dẫn từ từ a mol CO2 vào dung dịch có chứa b mol Ba(OH)2.Sau phản ứng thu được những chất gì và có khối lượng bao nhiêu mol theo a và b Mọi người giúp em vs ạ em sẽ chọn ctlhn

‘Come to our party on Friday night,’ they said. INVITED

‘Tidy it up and go to sleep,’ dad told us. ORDERED

‘I have a collection of sports cars,’ Eric said. BOASTED

Giups em câu 9, 10 với ạ em cần gấppp