Gọi số thí sinh là x ( \(\inℕ^∗\) ; học sinh ) và số phòng thi là y ( \(\inℕ^∗\); phòng )

+) Nếu mỗi phòng chỉ có 25 học sinh thì có 14 học sinh chưa có phòng thi: 

=> x = 25.y + 14  (1) 

+) Nếu mỗi phòng có 26 học sinh thì phòng cuối cùng chỉ có 5 bạn: 

=> x = 26 ( y - 1) + 5  (2 )

Từ (1) ; (2) ta có hệ: \(\hept{\begin{cases}x-25y=14\\x-26y=-21\end{cases}}\Leftrightarrow\hept{\begin{cases}x=889\\y=35\end{cases}}\)( thỏa mãn)

Vậy có 889 thí sinh và 35 phòng thi

1.      The teacher will be very angry if you …don't do………………………… (not do) your homework.

2.      If he …told…………………………….. (tell) me, I could help him.

3.      If you don’t water the flowers, they …will die……………………………………… (die).

4.      If you didn’t water the flowers, they …would die………………………………………(die).

5.      I ……would come………………………………….. (come) if I had time.

6.      If you don’t hurry,  you ……will miss………………………………….. (miss) the bus.

7.      If I …were you………………………… (be) you, I wouldn’t buy that car.

8.      He will play tennis if the weather …is………………………………. (be) good.

9.      I would be very happy if she ………was…………………………. (be) my sister.

10.  She could win the race if she …tried………………………………. (try).

11.  If he …goes…………………….. (go) to bed early, he will get up early.

12.  If he touches this wire, he …will get…………………………….. (get) a shock.

13.  You will get wet if it …rains………………………… (rain).

14.  If I knew, I …would come……………………………… (come) earlier.

15.  I wouldn’t say it if I …were…………………….. (be) you.

16.  What will you do if you …get……………………………… (get) a bad mark?

17.  If she …wears……………………….. (wear) a necklace, her dress will look better.

18.  If you go near the dog, it …will bite……………………………. (bite) you.

19.  Bodrum …would be…………………… (be) ideal for a holiday if it weren’t so crowded.

20.  He will be ill if he …eats…………………….. (eat) so much.

21.  If she ……reads………………………. (read) the book carefully, she will understand it.

22.  The children can stay up late if they ……are………………….. (be) good.

23.  If the dinner isn’t ready, I …will go……………………….. (go) out.

24.  We would die if the plane ……crashed………………………….. (crash).

Hok tốt !

1. The teacher will be very angry if you don't do your homework.

2. If he told me, I could help him.

3. If you don’t water the flowers, they will die.

4. If you didn’t water the flowers, they would die.

5. I would come if I had time.

6. If you don’t hurry, you will miss the bus.

7. If I were you, I wouldn’t buy that car.

8. He will play tennis if the weather is good.

9. I would be very happy if she were my sister.

10. She could win the race if she tried.

11. If he goes to bed early, he will get up early.

12. If he touches this wire, he will get a shock.

13. You will get wet if it rains.

14. If I knew, I would come earlier.

15. I wouldn’t say it if I were you.

16. What will you do if you get a bad mark?

17. If she wears a necklace, her dress will look better.

18. If you go near the dog, it will bite you.

19. Bodrum would be ideal for a holiday if it weren’t so crowded.

20. He will be ill if he eats so much.

21. If she reads the book carefully, she will understand it.

22. The children can stay up late if they are good.

23. If the dinner isn’t ready, I will go out.

24. We would die if the plane crashed.

học tốt

giúp với

Gọi nghiệm chung đó là x0

Có x0^2=mx0-2m-1

     x0(mx0-2m+1)-1=0

<=>x0^2+2=mx0-2m+1

      x0(x0^2+2)-1=0

Đến đây bạn tìm ra x0 rồi thay vào tìm m nhé