Ken's new classmate is likely to be invited to his birthday party

\(\dfrac{1}{2.5}+\dfrac{1}{5.8}+\dfrac{1}{8.11}+...+\dfrac{1}{92.95}+\dfrac{1}{95.98}\)

\(=3\left(\dfrac{1}{2}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{8}+...+\dfrac{1}{92}-\dfrac{1}{95}+\dfrac{1}{95}-\dfrac{1}{98}\right)\)

\(=3\left(\dfrac{1}{2}-\dfrac{1}{98}\right)=\dfrac{3.24}{49}=\dfrac{72}{49}\)

lúc nào cũng bắt bẻ z, làm một lúc dài quá không có hứng nên chia ra hai lần á .-.

1. I wish I had to study

2. I wish we hadn't have a lot of homework yesterday

3. I wish it didn't rain a lot

4. I wish it hadn't been very cold last night

5. I wish they didn't work slowly/ they worked fast

6. I wish I was good at English

7. I wish he didn't study badly/studied well

8. I wish he liked playing sports

9. I wish he would come here

10. I wish today was a holiday

I.REWRITE

1. He used to love me

2. They used to go to schook by bike when they were young

3. I used to eat meat

4. Lan often cried a lot when she was small

5. My father often drove to work when he lived in Japan

6. David no longer has long hair

7. Her mother used to get up early

8. He used o eat lots of ham

9. We used to live in country in 1980s, but now we live in HCM City

10. Nam used to hate school when he was young, but now he likes school

*Ta có \(\cos^2a+\sin^2a=1\)

\(\Rightarrow sina=\sqrt{1-\cos^2a}=\sqrt{1-\left(\dfrac{20}{29}\right)^2}=\dfrac{21}{29}\)

*Ta có \(\tan a=\dfrac{\sin a}{\cos a}=\dfrac{21}{29}:\dfrac{20}{29}=\dfrac{21}{20}\)

*Ta có \(\cot a.\tan a=1\Rightarrow\cot a=\dfrac{1}{\tan a}=\dfrac{20}{21}\)

Bạn ơi, bạn cần làm câu nào?

listening