Giúp mình bài 2 với , mình cần gấp .

. Để trung hoà hết 500ml dung dịch chứa NaOH 1M và Ba(OH)2 0,5M cần 100ml dung dịch HCl. Tính nồng độ mol dung dịch HCl đã dùng trình bày chi tiết và rõ rang => 5* và ctlhn

giúp em với ạ pleaseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

tổng của hai chữ số là 127989 ,nếu thêm vào số hạng thứ nhất 1286 thì tổng mới sẽ bao nhiêu ?

mọi người giúp mình zờiaffkfkakj

các anh chị gia sư ơi , giải hộ em câu này với ạ ?

. Nhiệt độ ở mặt đất đo được khoảng 300C. Biết rằng cứ lên 1km thì nhiệt độ giảm đi 50C a.      Hãy lập hàm số T theo h, trong đó T tính bằng độ (0C) và h tính bằng ki-lô-mét (km) b.     Hãy tính nhiệt độ khi ở độ cao 3km so với mặt đất.

Giup Mình với bài 16 bài 17 sgk trang 85 toan tập 1 Bài 16 (trang 75 SGK Toán 8 Tập 1): Cho tam giác ABC cân tại A, các đường phân giác BD, CE (D ∈ AC, E ∈ AB). Chứng minh rằng BEDC là hình thang cân có đáy nhỏ bằng cạnh bên. Bài 17 (trang 75 SGK Toán 8 Tập 1): Hình thang ABCD (AB // CD) có góc ACD= góc BDC Chứng minh rằng ABCD là hình thang cân.

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1. He can't go out because he has to study for his exam.  If ................................................................................................................................................................ 2. She is lazy so she can't pass the exam.  If ................................................................................................................................................................. 3. He smokes too much; that's why he can't get rid of his cough.  If ................................................................................................................................................................ 4. I can't play football this afternoon because I felt tired.  If ................................................................................................................................................................. 5. Olga and Ivan weren't paying attention, so they didn't see the sign marking their exit from the highway.  If ................................................................................................................................................................. 6. She can't be employed because she doesn't have a college degree.  If ................................................................................................................................................................. 7. She walked to the meeting. She was late.  If ................................................................................................................................................................ 8. Unless you promise to return back, I won't lend you.  If ................................................................................................................................................................ 9. We put off our trip because the weather was terrible.  If ................................................................................................................................................................ 10. Sally doesn't know what she has to do for homework because she was absent from school on Friday.  If ................................................................................................................................................................. 11. If you do not like this one, I'll bring you another.  Unless ......................................................................................................................................................... 12. Martin failed his driving test last week because he was very nervous.  But for......................................................................................................................................................... 13. He will pay me tonight; I will have enough money to buy a car.  If ................................................................................................................................................................ 14. Leave me alone or I'll call the police.  If ................................................................................................................................................................ 15. If you arrive at the office earlier than I do, please turn on the air-conditioner.  Should......................................................................................................................................................... 16. He died so young; otherwise, he would be a famous musician by now.  Had it .......................................................................................................................................................... 17. The car breaks down so often because you don't take good care of it.  Were you ................................................................................................................................................... 18. Don’t tell lies to your boss or you'll be fired at once.  If ................................................................................................................................................................. 19. He didn't revise all his lessons, so he failed the exam.  Had ........................................................................................................................................................... 20. Rita is exhausted today because she didn't get any sleep last night.  If .................................................................................................................................................................