A = \(\dfrac{x+13}{x+2}\)  (đk \(x\) ≠ -2)

Em cần làm gì với biểu thức này?

c: \(C=\frac14+\frac{1}{28}+\frac{1}{70}+\frac{1}{130}+\frac{1}{208}+\frac{1}{304}\)

\(=\frac{1}{1\cdot4}+\frac{1}{4\cdot7}+\frac{1}{7\cdot10}+\frac{1}{10\cdot13}+\frac{1}{13\cdot16}+\frac{1}{16\cdot19}\)

\(=\frac13\left(\frac{3}{1\cdot4}+\frac{3}{4\cdot7}+\cdots+\frac{3}{16\cdot19}\right)\)

\(=\frac13\left(1-\frac14+\frac14-\frac17+\cdots+\frac{1}{16}-\frac{1}{19}\right)\)

\(=\frac13\left(1-\frac{1}{19}\right)=\frac13\cdot\frac{18}{19}=\frac{6}{19}\)

Question 1: Because the water is polluted, the fish are dead.

Question 2: Because households dump waste into the river, it is polluted.

Question 3: The picture was painted by a local artist.

Question 4: A new house will be rebuilt in the area.

Question 5: If I weren't busy, I could attend your birthday party.

Question 6: If Nigel had satellite TV, he could watch the game.

II/ Write a paragraph (80-100 words)

Learning English effectively requires daily practice and the right methods. First, to learn vocabulary efficiently, you should put new words into different situational sentences and practice writing them daily. Second, reading English stories and books helps widen your vocabulary and retain words much longer. Finally, listening to online English programs every day is an excellent way to imitate native speakers' pronunciation and improve your listening skills. By combining these three habits, you will quickly enhance your overall English proficiency.

9a

10d

11d (câu này thực tế 4 phương án đều chưa thích hợp)

12a

13a

14c

15d

em cần tất cả các bài à

chiều này cx đi hok à

C gửi bài nà! Tích cho c nha!b2:b3:b4:

\(BC=\sqrt{8^2+5^2}=\sqrt{89}\approx9,4\left(cm\right)\)

Chọn C