Theo hình, ta có: \(DI=\frac13\times DC\)

mà DC=AB(ABCD là hình chữ nhật)

nên \(\frac{DI}{AB}=\frac13\)

Vì DI//AB

nên \(\frac{OD}{OB}=\frac{OI}{OA}=\frac{DI}{AB}=\frac13\)

=>\(\frac{DO}{DB}=\frac14\)

=>\(S_{DOI}=\frac14\times S_{DBI}\)

=>\(S_{DBI}=4\times S_{DOI}=4\times160=640\left(\operatorname{cm}^2\right)\)

Ta có: \(DI=\frac13\times DC\)

=>DC=3DI

=>\(\)\(S_{DBC}=3\times S_{DBI}=3\times640=1920\left(\operatorname{cm}^2\right)\)

ABCD là hình chữ nhật

=>\(S_{ABCD}=2\times S_{DBC}=2\times1920=3840\left(\operatorname{cm}^2\right)\)

2 Is your family with you hear

3 Does your wife enjoy athletics

4 Do you like life here in Italy?

5 Are you worried about the Italian Champion, Giacomo Zanetti

6 Dp you have any advice for young athletes

2. Is your family here with you?

Yes, it is

3. Does your wife enjoy atheletics

Yes, she is

4. Do you like life here in Italia?

No, I don't

5. Are you worried about....?

Yes, I am

6. Do you have any advice for young athletes?

Yes, I do

Yes, No quest nên bạn có thể tùy ý trl nhé!

Tổng là : 36 x 2 = 72 

 Số kia là : 72 - 50 = 22

~ HT ~

4: Ta có: x+2x+...+18x=1368

\(\Leftrightarrow153x=1368\)

hay \(x=\dfrac{152}{17}\)

2KMnO₄ → K₂MnO₄ + MnO₂ + O₂

Part 3

I

1 T

2 F

II

3 My family can receive much happiness from doing volunteer

4 My family raises some fund for them, and also cook meal for them

Part IV

I

1 Although I was tired last night, I stayed up late to watch a game show

2 Ha noi is smaller than HCM City

II

1 Sleep more, but try to wake up at the usual time

2 Be careful with what you eat and drink

III

1 - B

2 - D

3 - A

4 - E

5 - F

B

6 so

7 or

8 because

9 and

10 more