1 C

2 B

3 B

4 A

5 B

6 B

7 D

8 A

9 B

10 C

11 B

1. He came here by taxi but I travelled in my car.

2. Please sign your name at the bottom of the paper.

3. At the end, the prince fell in love with the princess.

6. At the end, the prince became the king of the country.

7. At the beginning of the class, we frequently had to clean the floor and erased the board.

8. At the beginning, all the students sang songs to get started.

1 more worried

2 more

3 greener

4 more optimistically

1. more worried

2. many

3. greener

4. more optimistically

hình như là hoàn hảo

 sai đề nha . Xin được sửa

\(\frac{0,75+0,6-\frac{3}{7}-\frac{3}{13}}{2,75+2,2-\frac{11}{7}-\frac{11}{13}}\)

\(=\frac{\frac{3}{4}+\frac{3}{5}-\frac{3}{7}-\frac{3}{13}}{\frac{11}{4}+\frac{11}{5}-\frac{11}{7}-\frac{11}{13}}\)

\(=\frac{3\left(\frac{1}{4}+\frac{1}{5}-\frac{1}{7}-\frac{1}{13}\right)}{11\left(\frac{1}{4}+\frac{1}{5}-\frac{1}{7}-\frac{1}{13}\right)}=\frac{3}{11}\)

chât vái lùn

chất cái dell j

Ta có : \(\tan\left(x\right)=\frac{\sin\left(x\right)}{\cos\left(x\right)}\)

\(\Leftrightarrow\tan^2\left(x\right)=\left(\frac{\sin\left(x\right)}{\cos\left(x\right)}\right)^2\)

\(\Leftrightarrow\tan^2\left(x\right)=\frac{sin^2\left(x\right)}{\cos^2\left(x\right)}\)

Và ta có : \(\cos^2\left(x\right)+\sin^2\left(x\right)=1\)

\(\Leftrightarrow\cos^2\left(x\right)=1-\sin^2\left(x\right)\)

VT: \(\tan^2\left(x\right)-\sin^2\left(x\right)\cdot\tan^2\left(x\right)\)

\(=\tan^2\left(x\right)\cdot\left(1-\sin^2\left(x\right)\right)\)

\(=\frac{\sin^2\left(x\right)}{\cos^2\left(x\right)}\cdot\cos^2\left(x\right)\)

\(=\sin^2\left(x\right)=VP\)(đpcm)

(chúc bạn học tốt)