`C=2^100-2^99-2^98-2^97-...-2^2-2-1`
`-> C= 2^100-(2^99+2^98+2^97+...+2^2+2+1)`
- Đặt `D=2^99+2^98+2^97+...+2^2+2+1`
`-> 2D= 2^100+2^99+2^98+...+2^3+2^2`
`-> 2D-D=(2^100+2^99+2^98+...+2^3+2^2+2)-(2^99+2^98+2^97+...+2^2+2+1)`
`-> D=2^100-1`
- Ta có : `C=2^100-D`
`-> C=2^100-(2^100-1)`
`-> C=2^100-2^100+1`
`-> C=1`
.....
Cảm nhận đoạn đầu bài thơ vội vàng Giúp e vs ạ
|2x+1| - 10 = -458 Hi các bạn, mik. Là tvm
Giúp mình bài 6 và bài 7 Cảm ơn trước
nhân xét về dan số Bắc Mĩ 2017
mk hỏi câu này 5 lần rùi huhu......ai đó giúp mk câu b vs! pls help me!!
giải các pt sau:1) 3x – 2 = 2x – 3 2) 7 – 2x = 22 – 3x 3) 8x – 3 = 5x + 12 4) x – 12 + 4x = 25 + 2x – 1 5) x + 2x + 3x – 19 = 3x + 5
1. The Second World War _______ in 1939. A. turned up B. took out C. brought about D. broke out 2. “We'd better _______ if we want to get there in time.” A. take up B. put down C. speed up D. turn down 3. I could not _______ the lecture at all. It was too difficult for me. A. make off B. take in C. get along D. hold on 4. My mother had to work 12 hours a day in a factory just to ________. A. tighten the belt B. make ends meet C. call it a day D. break the ice 5. He is coming _______ a cold after a night out in the rain. A. across with B. down with C. away from D. up with
1. We _______ with a swim in the lake. A. gave in B. cooled off C. got out D. took up 2. They’re staying with us _______ the time being until they can afford a house. A. during B. for C. at D. in 3. Since he failed his exam, he had to _ for it again. A. take B. sit C. make D. pass 4. “Why don’t you sit down and _______?” A. make yourself at peace B. make it your own home C. make yourself at home D. make yourself at rest 5. He never lets anything _______ him and his weekend fishing trip. A. come among B. come between C. come up D. come on
Hoàn thành tiến trình phát triển của khởi nghĩa Lam Sơn các năm 1416,1418,1421,14323,1424,1425,1426,1427,1428.
1. I accidentally _______ Mike when I was crossing a street downtown yesterday. A. caught sight of B. kept an eye on C. paid attention to D. lost touch with 2. My mother told me to _______ for an electrician when her fan was out of order. A. send B. write C. rent D. turn 3. It is very important for a firm or a company to keep _______ the changes in the market. A. pace of B. track about C. touch with D. up with 4. The forecast has revealed that the world’s reserves of fossil fuel will have _______ by 2015. A. taken over B. caught up C. used off D. run out 5. Even if you are rich, you should save some money for a _______ day. A. windy B. rainy C. foggy D. snowy
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