Kể tên một số danh nhân Hà Nội từ thế kỷ 16 đến thế kỷ 20

Cho x+y+z=1.Chứng minh GTBT sau không phụ thuộc vào giá trị của biến
P=\(\dfrac{\left(x+y\right)^2}{xy+z}\).\(\dfrac{\left(y+z\right)^2}{yz+x}\).\(\dfrac{\left(z+x\right)^2}{zx+y}\)

Cho x+y+z=1.Chứng minh GTBT sau không phụ thuộc vào giá trị của biến
P=\(\dfrac{\left(x+y\right)^2}{xy+z}\).\(\dfrac{\left(y+z\right)^2}{yz+x}\).\(\dfrac{\left(x+z\right)^2}{zx+y}\)\(\dfrac{\left(x+y\right)^2}{xy+z}\)

Cho biểu thức D=(\(\dfrac{a-1}{3a+\left(a-1\right)^2}\)-\(\dfrac{1-3a+a^2}{a^3-1}\)-\(\dfrac{1}{a-1}\)) : \(\dfrac{a^2+1}{1-a}\)
a) Tìm những giá trị của a để D xác định
b)Rút gọn D
c)Tìm giá trị của a để \(\dfrac{1}{D}\)nhỏ nhất và tìm giá trị nhỏ nhất đó

Complete the following sentences with could/should/shouldn't/must+have+P2 or should/must " infinitive
1. This computer isn't fast enough,I know I _________ a better one,but i didn't have enough money when i bough this last mont (buy)
2.Why did you stay at the hotel when you went to the New York? You _____ with Barbara.(stay)
3.Jack fell of a ladder yesterday but he's all right.He's lucky.He ________ him self badly(hurt)
4. The situation was bad but it ______ worse(be)
5.Carol ______very bored in her job.She does the same thing everyday(get)

Using "CAN/COULD and BE ABLE TO " to complete the following sentences
1.Sorry teacher,I _____do it yet
2.The fishing boat sank but luckily all the crew________ save themself
3. Kemal _________afford this watch.It's too expensive.
4. She ____swim.The learnt how to swim when she was.
5. Sinan _______find the password after three attempts

Using "CAN/COULD and BE ABLE TO " to complete the following sentences
1.I _______remember his name
2.Diana______play the piano.
3.She will ______come on holiday next month her parent give her permission
4.They _________go.The weather was too bad
5. A:Can you lend me some money?
B: Sorry.I _____.I haven't got any either

Ex: Rewrite the sentences in the same meaning.
1.The report must be on my desk tomorow.(has)
-> The report...........
2. I managed to finish all my home work(able)
-> I ............
3.The best thing for you to do is to sit down(better)
-> You............

Ex1:Rewrite the sentences in the came meaning
1.Maybe you will need to buy a ticket for your child.
2.It is essential that all new soldiers have a medical examination.
3.Foreigners don't have to register for military service.

Cho x≠0,2,-2,Rút gọn rồi tính GTBT
A= (\(\dfrac{4}{x-2}\)-\(\dfrac{3}{x+2}\)) :\(\dfrac{x+14}{x^2}\). (Tại x= -3 )