Đáp án+Giải thích các bước giải:
↓↓↓
S = 1+2+22+23+…+262+263
S=(1+2)+(22+23+...+262+263)
Ta tính dãy C=22+23+...+262+263
Dãy C có số số hạng là: (263−22):1+1=242
Tổng của dãy C là:(22+263)×242:2=34485
Vậy S = (1+2)+34485=3+34485=34488
`S = 1+2+22+23+…+262+263``S=(1+2)+(22+23+...+262+263)`ta tính vế phải :
`=> S=22+23+...+262+263`Dãy S có số số hạng là:
`(263−22):1+1=242`Tổng của dãy S là:
`(22+263)×242:2=34485`Vậy `S = (1+2)+34485=3+34485=34488`
1. It last rained here two months ago. A. It hasn’t rained here for two months B. There was no rain here two months ago C. It has rained here for two months D. It hasn't rained here for two months 2. She doesn’t speak Spanish so she cannot work for them. A. If she speaks Spanish, she can work for them B. If she spoke Spanish, she could work for them C. As she doesn't speak Spanish, she can work for them D. She can work for them if she spoke Spanish 3. He will die if nobody brings him to hospital at once. A. He will die unless he is brougt to hospital at once B. He will be saved if he isn't brought to hospital at once C. Since nobody brings him to hospital at once, he will die D. He is brought to hospital at once, so he won't die 4. "Please wake me up at 6 tomorrow morning", I said to my mother. A. I said to my mother to wake me up at 6 the next morning B. I told my mother that I would wake up at 6 the next morning C. I promised my mother to wake up at 6 the next morning D. I asked my mother to wake me up at 6 the next morning 5. The garage is going to repair the car for us next week. A. We are repairing the car in the garage next week B. The car is being repaired by the garage next week C. We are having the car repaired by the garage next week D. We are having the garage to repair the car next week 6. Mr. Pike used to live in this town. We bought his land. A. Mr. Pike, we bought his land, used to live in this town B. Mr. Pike, whose land we bought, used to live in this town C. Mr. Pike, his land we bought, doesn't live in this town D. Mr. Pike from whom we bought land doesn't live in this town 7. The test was very difficult. We couldn't finish it A. It was such a difficult test that we couldn't finish it B. The test was too difficult that we couldn't finish it C. We couldn't finish the test; therefore, it was so difficult D. We couldn't finish the test; as a result, it was so difficult 8. The volunteers won't come back to this area soon. A. If only the volunteers came back to this area soon B. We hope the volunteers wouldn't come back to this area soon D. We wish the volunteers will come back to this area soon D. We wish the volunteers would come back to this area soon
Hiiiiiiiii Giúp mềnh vs nhé !!!!
Nêu chức năng của đại não( chức năng của từng vùng) Mong mng giúp em ạ
`1 + 78/9 + x = 1` .................
Cho tệp văn bản 'ANH.TNP' gồm nhiều dòng, mỗi dòng chứa số nguyên. Viết chương trình đọc dữ liệu từ tệp 'ANH.INP' .Hãy đếm (tổng/trung bình) các số chẵn (lẻ) và ghi kết quả vào tệp 'KQ.OUT' Mình cần gấp ạ.
Are you and your mother / sisters / brother / friends interested in similar thing ? What are they .
toi sẽ ko nói cho bạn biết là * tôi rất ghét bạn đou * nói sợ bạn buồn T-T Vẽ chibi
x . 3 + 2 + 2 = 9 ................
The children agreed to divide into four groups A. The B. Agreed C. To divide D. to Each of the tourists are going to be given a guidebook to Spain A. tourists B. are going to C. given D. to tìm lỗi sai và sửa lại
Một người đi xe máy từ a đến b. Nếu đi với vận tốc 40km/h thì 18h đến nơi. Nếu đi 30km/h thì 18h30 đến nơi. Tính độ dài quãng đường ab. Nhờ các bạn giúp mình
Loga.vn - Cộng Đồng Luyện Thi Trực Tuyến