Cho phương trình: x² - 2(m +1)x + 2m +3=0. Tìm m để phương trình có 2 nghiệm x₁, x₂ thỏa mãn: lx_{1 -} x₂l = 2

Cho phương trình: x² - mx +m - 1=0. Gọi x₁, x₂ là 2 nghiệm của phương trình. Tìm GTLN: P = \(\dfrac{2x_{1}x_{2} + 3}{x_{1}^2 + x_{2}^2 +2(1+ x_{1}x_{2})}\)

Cho 2 phương trình: x² + mx + 1 = 0 (1); x² + x + m = 0 (2)  Tìm m để:

a, 2 phương trình có nghiệm tương đương

b, 2 phương trình có nghiệm chung

IV. Rewrite the sentences

1. cars cause pollution but people still want them. (although)

=> .........................................................................................................................................................

2. We took many pictures although the sky was cloudy. (in spite of)

=> .........................................................................................................................................................

3. Although he is wealthy, he is not spoiled. (despite)

=> .........................................................................................................................................................

4. Even though she had a poor memory, she told interesting stories to the children. (despite)

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5. Though he has been absent frequently, he has managed to pass the test. (despite)

=> .........................................................................................................................................................

6. My sister will take a plane even though she dislikes flying. (in spite of)

=> .........................................................................................................................................................

7. He isn’t happy although he is very rich. (despite)

=> .........................................................................................................................................................

8. Even though he got a good job, he was not satisfied. (despite )

=> .........................................................................................................................................................

9. Although he often tells lies, many people believe him. (despite)

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10. Mary didn’t go to school yesterday because she was sick. (because of)

=> .........................................................................................................................................................

11. She went to bed early because she felt tired . (because of)

=> .........................................................................................................................................................

12. Margaret stayed at home because her mother was sick. (because of)

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13. I couldn’t read the letter because the room was dark. (because of)

=> .........................................................................................................................................................

14. The train come late because it was foggy. (because of)

=> .........................................................................................................................................................

15. The train was late because the fog was thick. (because of)

=> .........................................................................................................................................................

16. I can’t sleep because the weather is hot. (because of)

=> .........................................................................................................................................................

17. Because there was a traffic accident, I went to school late. (because of)

=> .........................................................................................................................................................

18. Because there is a shortage of meet, we had to live on beans. (because of)

=> .........................................................................................................................................................

19. Because there was a lack of water, many trees died rapidly. (because of)

=> .........................................................................................................................................................

20. She walked slowly because her leg was injured. (because of)

=> .........................................................................................................................................................

21. She didn’t eat much though she was hungry . (despite)

=> .........................................................................................................................................................

22. He couldn’t solve the problem though he is good at math. (despite)

=> .........................................................................................................................................................