Bổ sung: khu đất hình vuông có chu vi là 432m

``

Chiều dài của khu đất là:

`432:4=108 (m)`

Diện tích khu đất là:
`108 xx 108 =11664 (m^2)`

Đáp số: `11664 m^2`

a. k=23, j=7

b. k=8, j=4

c. k=20, j=8

`2:x-1/3=2/5`

`2:x=2/5+1/3`

`2:x=11/15`

`x=2:11/15`

`x=30/11`

-5 -> -4 = 1 lần

-4 -> -3 = 1 lần

...

2 -> 3 =1 lần

`=>` Tổng = 8 lần

Số phần tử của không gian mẫu: `n(Ω) = C_12^4=495`

A: "4 bông được chọn có đủ 2 loại"``

`=> overline(A)`: "4 bông được chọn không đủ 2 loại"

``

TH1: không có hoa hồng

`=> C_7^0 . C_5^4=5`

TH2: không có đồng tiền

`=> C_7^4 . C_5^0 = 35`

`=>n(overline(A))=5+35=40`

``

`=> P(A)=1-P(overline(A))=1-40/495=91/99`

My hobby is watching TV. I like it because it's so much fun. There are many interesting things: cartoon programs on my favorite airtime - 6 pm, dramas which I can watch with my family, educational shows which I can learn from,... Watching TV is not bad, but doing it for hours is harmful.

1. This letter will be translated into Vietnamese.

2. It is impossible to travel around the city in a day. 

3. Would you mind if I took a photograph?

4. Do you mind helping me move this table? 

5. The ruler which is made of metal is mine.

6. The man who is walking with a crutch now had an accident yesterday.

7. The teacher who is talking to the principal is in charge of my class.

1. Car tires are recycled to make pipes and floor covering.

2. Milk bottle can be reused after being cleaned.

3. How about going to TV market? 

4. DO you mind closing the window?

5. He is interested in the history of Asian.

14. B

15. A

16. D

17. B
18. B
19. A
20. D