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Đề có sai ko bạn

ax^2 + (ab+1)x + b=0

ax^2 + abx + x + b =0

ax(x+b) + (x+b) =0

(x+b)(ax+1)=0

=> \(\left\{{}\begin{matrix}x+b=0\\ax+1=0\end{matrix}\right.\)=>\(\left\{{}\begin{matrix}x=-b\\x=\frac{-1}{a}\left(a\ne0\right)\end{matrix}\right.\)

Vậy phuơng trình trên luôn có nghiệm

1. You have to speak English.

2. When does he have to go home?

3. They have to clean the bathroom

4. When does she have to ride her bike?

5. Billy has to work in the supermarket.

Dear, Jennie!

Hello my friends, it's a long time I haven't write for you. Last week, I went to Paris and I want to show you about this city. Paris is a beautifull and romantic city so it's a perfect place to date. You can find many interesting thing to do in Paris like shopping because Paris has many shops, supermarkets,... with all thing or you can drinking coffee and reading your favourite book;... but I think the most I like it's walking arround the Effel tower to thinking about my life. You know, Paris is the capital of French and it's the largest cit in French. Paris is not only important with French, it's also an impotant city of the world beacace advantages that have gain. I was very happy in the time I lived in Paris and I find it's interesting place to go. Let write for me about your favourite city.

I hope to read your letter.

Your best friend

Anna

1. A

2. A

3. C

4. C

5. C

6. C

7. A

8. C

9. B

10. C

11. D

12. B

13. C

14. C

15. D

16. A

17. C

18. A

19. B

20. B

21. D

22. B

23. C

24. C

25.

A

26. D

27. C

28. A 29. A

30. D

31. A

32. A

33. A

34. C

35. B

1. It's ages since we last met

2. Do you mind not leaving your paper all over the table? Oh, sorry. I'll take them all with me when I go.

3. I've decided to repaint this room. Oh,have you? What colour have you painted?

Cho a,b,c là số thực dương thỏa mãn: a+b+c<= căn 3.

Tìm GTLN của M= \(\frac{a}{\sqrt{a^2+1}}+\frac{b}{\sqrt{b^2+1}}+\frac{c}{\sqrt{c^2+1}}\)

Tìm: x+y+z=2: 1/x +1/y +1/z = 1/2: 1/y^2 - z = 3/2