không có đề làm bằng niềm tin ak bạn 

nói cộc lốc zậy sao mà bik giúp bn dk nhệ

làm hộ mk bài 3 bà 4 nha

B1 và cái j

M nhớ hôm qua mik lm câu hình này r

Do a//b

\(\Rightarrow\widehat{A_1}+\widehat{B_1}=180^o\) (Trong cùng phía)

\(\Rightarrow70^o+\widehat{B_1}=180^o\)

\(\Rightarrow\widehat{B_1}=110^o\)

Bài 3.

Khoảng cách từ ảnh đến thấu kính:

\(\dfrac{1}{f}=\dfrac{1}{d}+\dfrac{1}{d'}\Rightarrow\dfrac{1}{6}=\dfrac{1}{12}+\dfrac{1}{d'}\)

\(\Rightarrow d'=12cm\)

Chiều cao ảnh: \(\dfrac{h}{h'}=\dfrac{d}{d'}\)

\(\Rightarrow\dfrac{1}{h'}=\dfrac{12}{12}\Rightarrow h'=1cm\)

\(\dfrac{4^6\cdot9^5+6^9\cdot120}{-8^4\cdot3^{12}-6^{11}}\)

\(=\dfrac{2^{12}\cdot3^{10}+2^{12}\cdot3^{10}\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}\)

\(=\dfrac{2^{12}\cdot3^{10}\cdot\left(1+5\right)}{2^{11}\cdot3^{11}\left(2\cdot3-1\right)}\)

\(=\dfrac{2\cdot6}{3\cdot5}=\dfrac{4}{5}\)

1. => Are you free tomorrow evening.

2. => What's our English teacher's address?

3. => February is the month between January and March.

4. => She's out at the moment. She'll be back at 8 o' clock.

5. => Lan feels happy because she has lots of friends.

6. => Let's meet in front of the school.

7. => Tell her I'll call her again.

8. => Would you like to see a film on Sunday morning?

9. => We study at a large school in Ha Noi.

10. => Lan and Mai are my close friends

giống sách Lưu Hoằng Trí quá, unit mấy thế

1. => Where will we meet? In front of our school gate.

2. => What is your date of birth, Lan? The first of October.

3. => How long will the party be? About one hour and a half.

4. => What is your phone number? 04 38459214.

5. => How old will you be on your next birthday, Mai? Fourteen.

6. => What time will the film start? At half past six.