B= 1+1/2(1+2)+1/3(1+2+3)+.....+1/x(1+2+.....+x) Tìm số nguyên dương x để B = 115

$\text{Tóm tắt và đưa ra một số dạng bài tập về ngữ pháp ở}$ $\text{Unit 2: Life in the countryside.}$

Mik đang cần gấp cảm ơn nhiều nha

mn làm hộ mình b8 với dc ko ạ, mik đg cần gấp ;-;

It is said that there is plenty of oil off our own coast. -> There is....

Chọn từ sai trong câu và sửa lại 1.she will study english at RMIT these days. 2.she's at her best when she will make such a big decision. 3.we was spending our next vacation in london next week. 4.Robert has arrived at our place tomorrow morning on the 10.30 train. 5.look! The seabirds glide on the sea surface whicb makes a beautiful sunset. 6.mike has phoned you more than one hour ago. 7.michale hasn't said a word with lisa this morning. 8.old ted has smoked twenty cigarettes a day till he gave up.

Mô tả cấu trúc và đặc tính lý hóa của nước? Vai trò của nước trong tế bào?

Anh chị làm giúp em với ạ . Em đang cần gấp . Bài 7 thảo luận nhìn ở bài 6 suy ra

Cho tam giác vuông EDC có EG = GF, kẻ GH vuông góc DF a) C/m H là trung điểm DF b) Cho ED = 4cm. Tính độ dài đoạn GH ****Nhanh nhé mk đag cần gấp

IV. Underline the correct answers. 1. I saw/ have seen that film already. 2. We went/ have gone to the movies three times last month. 3. Did you ever do/ Have you ever done volunteer work? 4. I had/ have had five tests so far this semester. 5. Linus did/ has done his homework before he went to sleep. 6. This is my grandparents’ house. They lived/ have lived here for more than 50 years. 7. She bought/ has bought a new mobile phone two days ago. 8. Did you see/ Have you seen Peter at the party last night? 9. I read/ have read this book twice and I still find it very interesting. 10. They didn’t play/ haven’t played very well yesterday. They lost the match.