1. There’s the lady. Her dog was killed.

There’s the lady whose dog was killed.

2. That’s the man. He’s going to buy the company.

That’s the man who is going to buy the company

3. He’s the person. His car was stolen.

He’s the person whose car was stolen

4. She’s the new doctor.The doctor’s coming to the hospital next week.

She's the new doctor who is coming to the hospital next week

5. She’s the journalist. Her article was on the front page of The Times.

She's the journalist whose article was on the front page of The Times.

6. They’re the people. Their shop burned down last week.

They’re the people whose shop burned down last week

7. That’s the boy. He’s just got a place at university.

That’s the boy who has just got a place at university.

1. This is the man I met in Paris.

2. I wanted the painting you bought.

3. This is the chair my parents gave to me

4. She’s the woman who telephoned the police.

5. He’s the person who wanted to buy your house.

6. We threw out the computer which never worked properly.

7. This is the lion being ill recently.

8. The man driving the car was badly injured. 

9. The children living in the next street broke the window. 

10. That’s the woman I was telling you about.

Bạn tải ảnh về máy, vào biểu tượng  để đăng ảnh lên CH nhé.

Bạn có file ảnh thì ms đăng đc chứ , ko có ảnh đăng câu hỏi bằng ảnh kiểu gì ?

https://i.imgur.com/EDfSREq.png (Link hình ảnh)

ko cóp chữ đc :<

đề này nè

Đáp án A

 mình là fan cuồng nên chắc chắn 100%

đáp án c.con ngựa này do quân hy lạp đóng bằng gỗ rồi đột nhập vào thành troy!

6 How often does your grandfather often listen to the radio

7 How often do you go to the gym

8 What did they send

9 What time did he leave the party

10 Where did he go

11 Who did he meet for coffee

12 Why did she called the firemen

13 How did he go to school

14 What does lan like doing

15 Where was your father last months

16 How much is the dictionary

17 How long did it take to finish the composition

18 Who bought a poster

What did Mrs Robinson by

19 Where is a restaurant

20 What did her neighbor give her

21 How was the homework yesterday

22 Do you have magaazine and newspapers

23 How often do you go to the movies

Bạn kiểm tra lại đề bài câu a, n=1 thì VT=1, VP=-1, nếu đề bài đúng thì vp phải là \(\dfrac{-\left(1\right)^{n-1}n\left(n+1\right)}{2}\)

\(n=1\Rightarrow VT=1=VP\)

Vậy mệnh đề đúng với n=1

Giả sử mệnh đề cũng đúng với \(n=k\left(k\in N\right)\), hay:

\(1^2-2^2+...+\left(-1\right)^{k-1}.k^2=\dfrac{\left(-1\right)^{k-1}.k.\left(k+1\right)}{2}\)

Ta cần chứng minh mệnh đề cũng đúng với \(n=k+1\) ,hay:

\(1^2-2^2+...+\left(-1\right)^{k-1}.k^2+\left(-1\right)^k.\left(k+1\right)^2=\dfrac{\left(-1\right)^k.\left(k+1\right)\left(k+2\right)}{2}\)

That vay:

\(VT=\dfrac{\left(-1\right)^{k-1}k\left(k+1\right)}{2}+\left(-1\right)^k.\left(k+1\right)^2=\dfrac{\left(-1\right)^{k-1}.k.\left(k+1\right)+2\left(-1\right)^k\left(k+1\right)^2}{2}\)

\(=\dfrac{\left(-1\right)^k\left(k+1\right)\left(-k+2k+2\right)}{2}=\dfrac{\left(-1\right)^k\left(k+1\right)\left(k+2\right)}{2}=VP\)

Vậy mệnh đề đúng với \(\forall n\in N\)

b/ \(n=7\Rightarrow VT=3^7=2187< 7!=5040\)

Vậy mệnh đề đúng với n=7

Giả sử mệnh đề đúng với \(n=k\left(k\in N;k\ge7\right)\),hay:

\(3^k\le k!\)

Ta cần chứng minh mệnh đề cũng đúng với \(n=k+1\) ,hay:

\(3^{k+1}\le\left(k+1\right)!\)

That vay:

\(3^k.3\le\left(k+1\right).k!\)

\(k>6\Rightarrow k+1>6\Rightarrow k+1>3\)

Ma \(3^k\le k!\)

\(\Rightarrow3^k.3\le\left(k+1\right).k!\Leftrightarrow3^{k+1}\le\left(k+1\right)!\)

Vậy mệnh đề đúng với \(\forall n\in N;n>6\)