80²-79²+78²-77²+....+2²-1
=(80²-79²)+(78²-77²)+...+(2²-1²)
=(80-79)(80+79)+(78-77)(78+77)+...+(2-1)(2+1)
=80+79+78+77+...+2+1
=80(80+1):2=3240
`80²-79²+78²-77²+....+2²-1`
`=(80²-79²)+(78²-77²)+...+(2²-1²)`
`=(80-79)(80+79)+(78-77)(78+77)+...+(2-1)(2+1)`
`=80+79+78+77+...+2+1`
`=3240`
Xin hay nhất !
16 mũ 4. 2 mũ7 8 mũ 2: 49 mũ 3 (0,3) mũ 3. 70 mũ 3 giúp mik vs ạ
Viết đoạn văn khoảng 200 từ nêu suy nghĩ của em về tình mẫu tử
Cho dãy số: 3; 8; 13; 18; ... a) Tính tổng 100 số hạng đầu tiên của dãy b) Số 158 là số hạng thứ bao nhiêu của dãy giải theo cách dễ hiêu nhất dành cho cấp 1 nha
DIễn biến, kết quả, ý nghĩa của trận đánh ngô quỳên trên sông bạch đằng
các cao nhân lm giúp mik bài2 dc ko ạ? cảm ơn trc ;-;
I/ Complete the conversations. Put in a to-infinitive ỏ an ing-form 1. A: Are you going to organize our trip? B: Yes, of course. I've agreed ________ it 2. A: You wear a uniform at work, don't you? B: Yes, I have to, although I dislike ________ it 3. A: Do you think they'll approve the plan? B: Yes, I'm quite sure they'll decide ________ it 4. A: What time will you be back? B: Oh, I expect __________ back sometime around nine. 5. A: Did I remind you about the dinner tonight? B: Yes, thank you. You keep _________ me. 6. A: Was your decision the right one, do you think? B: Yes, luckily. In the end it proved _________the best thing for everyone. 7. A: Do you still work at the post office? B: No, I gave up ______ there last year. 8. A: Have ICM bought the company? B: Well, they've offered_______it. 9. A: I'm sorry you had to wait all that time.' B: Oh, it's all right. I don't mind ______ it II/Put the verb into the correct form 1. I don't mind _______(walk) home but I'd rather ______(get) a taxi. 2. I can't make a decision. I keep ________(change) my mind. 3. He had made his decision and refused _______ (change) his mind. 4. The film was very sad. It made me ___________(cry). 5. It was a really good holiday. We really enjoyed ______(be) by the sea again. 6. They don't have much money. They can't afford_____(go) out very often. 7. Did I really tell you I was unhappy? I don't remember _______ (say) that. 8. Remember __________(phone) Tom tomorrow. III/Put the verb in the correct form, present simple or present proressive 1. A: What___________(you/ do)? B: I____________(write) to my parents. I ___________(write) to them every weekend. 2. A: Look, it________(snow). B: It's beautiful! This is the first time I've ever seen snow. It __________(not snow) in my country. 3. A: Oh, that's Adrian. He's new here. B: Really? Where ______________(he/ live)?_______(you know)? A: Yes. He ________ (live) in Milan, but now he _________(stay) with his aunt on Shirley Road. 4. A: What time_________ (you/ usually/ finish) work? B: Normally I_________(finish) work at five o'clock, but this week I ____________(work) until six to earn a bit more money. 5. A: How__________(you/travel) to work? B: I haven't got a car at the moment, so I ________(go) to work on the bus this week. Usually, I ______(drive) to work. 6. A: I think we're going the wrong way. B: I don't think so. The sun _________(rise) in the east, remember. It's behind us, so we_________ (travel) west. 7. A:___________(you look) for someone? B: Yes, I __________(need) to speak to Neil. Is he in? A: Yes, but I _________(think) he's busy. He ___________(talk) to the boss at the moment. 8. A: I_ ________(want) a new computer. I ________(save) up to buy one. B: But computers________ (cost) so much money. What's wrong with the one we've got? A: It_______(get) out of date now. 9. A: Your new dress________(look) very nice. B: Thank you. The trouble is it________(not/fit) properly. I _______(not/know) why I bought them, really. 10. A: What________ (you do)? B: I________ (taste) the sauce. It_______(taste) too salty.
chỉ làm câu 5,6,8 thui nha mình vote cho 5 sao
Nêu định nghĩa, và 5 ví dụ - Từ nhiều nghĩa (lớp 6) - Từ đồng âm (Lớp 6) - Từ đồng nghĩa (Lớp 6) - Từ trái nghĩa (Lớp 6) - Từ tượng hình, từ tượng thanh (Lớp 8) - Trường từ vựng (Lớp 8) - Thành ngữ (lớp 7) - Từ ngữ địa phương và biệt ngữ XH (Lớp 8) - Thuật ngữ (Lớp 9) - Sự phát triển của từ vựng (Lớp 9) - Trau dồi vốn từ (Lớp 9) Xin phép mọi người giúp em câu này nhanh em cần gấp ĐẦY ĐỦ! KHÔNG SPAM!
giải giúp mik câu 3 và giải thích nhé
Hóng bài làm chất lượng, đọc kĩ đề bài!!! Yêu cầu lập dàn ý Suy nghĩ về nụ cười trong cuộc sống Lập dàn ý: Gồm các phần - Giải thích -Biểu hiện - Ý nghĩa - Bàn luận mở rộng - Liên hệ bản thân CỐ gắng những dẫn chứng cập nhật năm nay
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