a) \(d\left(A;\Delta\right)=\dfrac{\left|4.1-3.3+2\right|}{\sqrt{4^2+\left(-3\right)^2}}=\dfrac{3}{5}\)

b) \(\overrightarrow{AB}=\left(-3;-2\right)\) là VTCP của đường thẳng d

PT tham số của d: \(\left\{{}\begin{matrix}x=1-3t\\y=3-2t\end{matrix}\right.\left(t\in R\right)\)

c) Đường tròn (C) có bán kính \(R=AB=\sqrt{\left(1+2\right)^2+\left(3-1\right)^2}=\sqrt{13}\)

PT đường tròn (C): \(\left(x-1\right)^2+\left(y-3\right)^2=13\)

7. C

8. D

9. A

10. B

MÌNH CẦN GẤP LẮMMMM ĐÓOOOO

MỌI NGƯỜI GIẢI CHI TIẾT ĐỪNG BỎ BƯỚC NÀO NHAAAAA, MÌNH CẦN GẤP THIỆT ÁAAAA

\(3\left(x-2\right)^2=x^2-4\)

\(\Leftrightarrow3\left(x-2\right)^2-\left(x-2\right)\left(x+2\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(3x-6-x-2\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(2x-8\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x-4\right)=0\)

\(\Leftrightarrow x-2=0\) hay \(x-4=0\)

\(\Leftrightarrow x=2\) hay \(x=4\)

-Vậy \(S=\left\{2;4\right\}\)

B

A

A

A

B 

7. B

9. A

11. A

a, 25/12

b,  25/72

a) = 3/4 + 4/3 = 25/12

b) = 3/8 - 16/9 = -101/72 * hình như hơi sai sai:"> *

In the age of technology, laptop is used widely. The laptop brings us a lot of benefits for our live. it is very versatile as it can do many things. firstly, it is portable. therefore, people can take it everywhere. secondly, it is economical so everyone don't have to spend too much money to buy it. besides, the laptop is a mean of entertainment. we can use it to listen to music, to chat with friends, to make video call with parents, to play games, and so on. last but not least, we can use laptop for studying. for example, the laptop can be used for researching topics on the Web or typing the assignment as well. In summary, laptop is definitely one of the greatest inventions in the world as well as the best thing in our society.

P/s: Mình nghĩ nói ngắn quá sẽ không có điểm cao lắm đâu, không cần nói quá dài hoặc quá ngắn. Chỉ cần đầy đủ ý trong bài là ok. Với lại khi nói bạn nhớ phải tự tin lên nha. FIGHTING!!!!