cho tam giác abc có a = 90 độ , ah vuông góc bc a) ah = 60 , ch = 27 tính bh , bc, ah , ac

Câu 1: Trong thành phần một oxit kim loại hoá trị III, nguyên tố k chiếm 70% khối lượng. Xác định công thức oxit Câu 2:Nêu tính chất hoá học của oxi ,hiđro, nước . Viết PTHH minh hoạ cho mỗi loại phản ứng sau: a) Oxi hoá một kim loại thành oxit kim loại b) Oxi hoá một phi kim thành oxit phi kim c) Kim loại tác dụng với nước tạo thành bazơ và khí hiđro d) Oxit bazơ tác dụng với nước tạo thành bazơ e) Oxit axit tác dụng với nước tạo thành axit f) Khử oxi của oxit kim loại tạo thành kim loại và nước g) Phân hủy một hợp chất bằng nhiệt ( nhiệt phân) h) Phân hủy một hợp chất bằng điện ( nhiệt phân)

apply for go on cheer up pull down dress up set up find out take off get over turn back 1. We've______________a really good restaurant near the central station. 2. You don't need to______________to go to the mall - jeans and a T-shirt are fine. 3. Professor Colin Evers______________a job at a famous university in Sydney. 4. We really can't______________living like this - we'll have to find a bigger house. 5. Mary was very unhappy last week, but she has______________now. 6. You need to______________your shoes before going inside the house. 7. They______________the old cinema to build a new shopping mall. 8. A committee has been______________to organize social events for the students. 9. It took me a few days to______________my flu. 10. The mountain climbers had to______________because they were exhausted.

Giúp mình giải bài toán này vs ạ

Giúp mình câu 3, 5, 6,7 vs mọi người ơi

70. Please forgive me for (not write) to you. 71. There is no point in (have) a car if you never use it. 72. It’s a waste of time (buy) thing you don’t need. 73. I shouted ( warn) people of the danger . 74. The President has a team of bodygaurds ( protect)him. 75. She is bound (pass) the exam. 76. He is difficult ( understand) 77. I was interested (hear) that Diane has got a new job. 78. We weren’t allowed (leave) the building 79. I’m looking forward to (go) away next week . 80. Mary promised (buy) me a drink. 81. Jonh made so much noise when I was trying (sleep). 82. It was a difficult question (answer) 83. It was very kind of you (do) my shopping for me. 84. She was the first (arrive) here. 85. You should avoid (travel) during rush hour. 86. We have all agreed (take) a pay cut so that our company will survive. 87. For the time being, the police won’t allow anyone (leave) the building 88. Personally, I wouldn’t dare (criticise) my boss. 89. We’ve delayed (fix) the date of the wedding (please) everybody. 90. The accused denied (be) anywhere near the bank during the robbery. 91. Visitors have been directed (not carry) cameras into the museum. 92. Most men dislike(wear) the same shirt 2 days running 93. Surely yopu just can’t fail (notice) the constant rise in the cost of living. 94. I don’t fancy(be) responsible for a party of school children for a week. 95. It’s hard (imagine) (live) without electricity. 96.I keep (leave) my glasses all over the place. 97. I’ve never managed (get) to the end of “War and Peace”. 98.I suggest (take) a taxi. 99. If we wish (visit) Canada before we’re old, we’d better start(save). 100. It’s hard (imagine) that anyone actually wants (work) down a mine

CÓ GIẢI THÍCH nhessssssssssssssssssssssssssssssssssssss

Làm ơn giải giúp em với ạ em đang cần gấp Em cảm ơn nhiều!!!

Cho em hỏi bài 1 với ab bài 2 ạ

tìm x để : lAl=A, A=(√x-1)/(√x+1)