Chứng minh : \(\sqrt{4+2\sqrt{3}}-\sqrt{4-2\sqrt{3}}=2\)

Rút gọn các biểu thức : a) \(\sqrt{\left(3+\sqrt{5}\right)^2}\)

b) \(\sqrt{\left(5-\sqrt{5}\right)^2}\)

c) \(\sqrt{\left(4-\sqrt{11}\right)^2}+\sqrt{11}\)

d) \(\sqrt{\left(\sqrt{8}-7\right)^2}-\sqrt{8}\)

Giai phương trình : \(\sqrt{x^2+1}=-3\)

Tìm GTNN của : \(\frac{4x^2-6x+1}{\left(2x-1\right)^2}\)

I.Change the following sentences into the passive voice. (chuyển sang câubịđộng)
1.People spend a lot of money on advertising everyday.
__________________________________________________________________________________________
2. Marry is cutting the cake with a sharp knife.
__________________________________________________________________________________________
3. The police haven’t found the murderer yet.
__________________________________________________________________________________________
4. They sold one of her paintings at $1,000.
__________________________________________________________________________________________
5. Tom was writing two poems.
__________________________________________________________________________________________
6. They will hold the meeting before the May Day
__________________________________________________________________________________________
7. The chief engineer was instructing all the workers of the plan.
__________________________________________________________________________________________
8. The boys broke the window and took away some pictures.
__________________________________________________________________________________________
9. The teacher is going to tell a story.
__________________________________________________________________________________________
10. They may use this room for the classroom.
__________________________________________________________________________________________
11. You mustn’t use the machine after 5.30 p.m.
__________________________________________________________________________________________
12. After class, one of the students always erases the chalk board.
__________________________________________________________________________________________
13. She often takes her dog for a walk.
__________________________________________________________________________________________
14. Nobody has ever treated me with such kindness.
__________________________________________________________________________________________
15. No one believes this story.
__________________________________________________________________________________________
16. They use milk for making butter and cheese.
_______________________________________