cho tam giác ABC vuông tại A biết AB =6 BC=10 kẻ đường cao AH của tam giác ABC gọi D và E lần lượt là chân các đường vuông góc kẻ từ H đến AB và AC tính DE

Câu 1: Rút gọn biểu thức P = (x - y)^2 + (x + y)^2 – 2.(x + y)(x – y) – 4x^2 Câu 2 : Phân tích các đa thức sau thành nhân tử: a/ x^3 – x^2y + 3x – 3y ; b/ x^3 – 2x^2 – 4xy^2 + x ; c/ (x + 2)(x+3)(x+4)(x+5) – 8 giúppppppppppppppppppppppppp

Giải hộ e vs ạ!!! Hứa vote 5 sao và ctlhn ạ!

alice và mèo freshie rất thích câu cá họ câu được 28 con cá và feshie câu ít hơn alice 4 con cá hỏi alice được mấy con cá

Tìm x: ( 4x ² - 25 ) ² - 9( 2x - 5 ) ²=0

Cho em hỏi xét nhiệm covid 19 thế nào ạ? Có đau ko ạ? NL: tòa nhà em đang có 1 người bị covid mà em lại ở tầng dưới nên pk xét nhiệm :(((

Giúp mình mỗi bài 3 thôi nhé mn

1. Unless you try your best, you won't be able to ___________ your classmates A. keep up with B. lose track of C. take care of D. put an end to 2. Our main agricultural _________ to export world wide are rice, coffee and rubber A. products B. produce C. production D. productivity 3. The Earth is the only planet with a large _________ of oxygen in its atmosphere. A. number B. quality C. amount D. size 4. To get a passport, you must send in your birth _________ and two photos. A. certificate B. license C. paper D. card 5. - "What would she like to do?" - "__________________" A. Thanks. I don't know B. Sorry, I have no idea. C. Why don't I know? D. Excuse me. Sorry for the mistake. 6. It's the matter of life and death. ________, we will give it serious consideration. A. As a consequence B. Generally C. However D. So that 7. _________ different in characteristics we are, we have been mutual friends since our childhood. A. Despite being B. Although C. Whatever D. However 8. We live in a friendly community and everyone gets _______ each other very well. A. up to B. on with C. down to D. out of 9. _______ have you been able to play the piano? A. When B. How many times C. Since when D. Why 10. The students are always excited _______ doing the experiment in their Physics class. A. with B. in C. about D. at 11. Your room is a mess! __________ it up at once. A. Arrange B. Make C. Tidy D. Do 12. Tomatoes can be used as _________ a green salad or a cooking vegetable. A .both B.such C.either D.neither 13. Going swimming every day can have very _________ effects. A. beneficial B. benefitial C. benefited D. unbenefitial 14. Do you think we’ll find a solution _________ the problem? A. to B. for C. of D. about 15. Take an umbrella with you _________ it rains on your way. A. though B. as if C. however D. in case 16. Sue was offered a job as a translator but she turned it down. The underlined words can be replaced by _________. A. accepted it B. refused it C. got it D. considered it 17. Not until the beginning of the twentieth century _________ all over world. A. the first bicycles used B. were the first bicycles usedC. the first using bicycles D. the first bicycles were used 18. She never lets you cook the meals, ___________? A. didn't she B. doesn't she C. did she D. does she 19. Indian is difficult to get used _________ with the chopsticks A. to eating B. to eat C. to be eaten D. eat 20. “Who is Mr. Madely?” -“I don't know. I’ve never heard _________ him”. A. about B. from C. after D. of GIÚP EM VỚIII Ạ

Giải giúp em với ạ, em đang cần gấp

Từ các số 6,7,8,5,3,9 có thể viết được bao nhiêu số có 6 c/s