cho tam giác abc trên cạnh ab và ac lấy điểm m n sao cho mb=2ma,NC=2NA . tính diện tích ABC biết diện tích tam giác AMN=12cm2

Dựa vào kiến thức đã học em hãy phân tích những lợi thế và khó khăn của Việt Nam khi trở thành thành viên của ASEAN?

Tìm a để A = 3/ 2+√a nhận giá trị nguyên

Giúp với ạ. Mình đang cần gấp. Cảm ơn ạ!!!

Giúp em bài 3, 4 với ạ. Toàn mấy câu ngắn^^

Cho tam giác ABC có góc A=90 độ(AB<AC).Kẻ AH vuông góc BC.Trên tia đối của tia HA lấy điểm D sao cho HD=HA.Trên tia BC lấy điểm K sao cho HK=HB a,Chứng minh tam giác AHK=tam giác DHB b,Chứng minh AK//BD c,Chứng minh AB=DB d,Kẻ KI vuông góc AC của tam giác AKC.Chứng minh ba điểm D,K,I thẳng hàng Giúp mik với!!!!!!!!!!!!Mik đang cần gấp!!!!!!!!!!!!!!!!

Giải giúp mk 2 bài lý nha! Thanks

2√2-y + √x+1 =4 √2-y -3√x+1=-5 hpt giúp mình với

1. She wishes her father ________ here now to help her. A. has been B. is being C. is D. were 2. Julie goes to bed late. her mother wishes _______. A. she went to bed early B. she went to bed late C. she doesn’t go to bed late D. she goes to bed early 3. My father won’t lend me his car. I wish _______ . A. he lent me his car B. he didn’t lend me his car C. he would lend me his car D. he wouldn’t lend me his car 4. We wish we _____ a large house, but we can’t afford it now. A. have B. had C. can have D. will have 5. I’m sorry I haven’t got any money on me. I wish I _______. A. I have got no money on me B. I have some money on me C. I had got no money on me D. I had some money on me 6. It’s a pity she didn’t take her doctor’s advice. She wishes ________. A. she took her doctor’s advice B. she had taken her doctor’s advice C. she takes her doctor’s advice D. she would take her doctor’s advice 7. My father is not free today. I wish ______. A. my father is free today B. my father won’t be busy today C. my father would be free today D. my father were free today 8. I’m afraid our team will lose the game today. I wish _______. A. our team would win the game today B. our team won the game today C. our team didn’t lose the game today D. our team had won the game today 9. My friends didn’t take part in the game. I wish _______. A. My friends took part in the game B. My friends would take part in the game C. My friends did take part in the game D. My friends had taken part in the game 10. She wishes he ______ his letter of application earlier. A. would write B. had written C. wrote D. would wrote

Tính: $lim_{x->0}(\frac{1}{sin^2x}-\frac{1}{x^2})$