bay hình như sai rồi:

 How many classroom does your school has?

=> How many classrooms does your school have?

2.

 I live near my school

- I don't live far my school

3a) My mother wants a bottle of cooking oil.

How many cooking oil does your mother want?

b) I play fooball every afternoon after school.

=> what do you play every afternoon after school?

c) We are never late for school in winter.

=> How often do we late for school in winter?

d) He often helps her mom do the housework.

Who does he often help do the housework ?

e) My father drinks coffee in the morning.

What does your father drink in the morning ?

g) Lan often help me with my homework.

Who often help me with your homework ?

Đặt \(\frac{1}{2^2}+\frac{1}{2^4}+\frac{1}{2^6}+...+\frac{1}{2^{100}}\)là A

Ta có :A = \(\frac{1}{2}\left(1-\frac{1}{2^{100}}\right)\)

Vì 1-...

bài này hinh như chia 7 dư 5

1) Let's meet. at the school gate. 

2) My father will go fishing with his friends tomorrow.

3) It's 7.00 now I am studying English in the classroom.

4) I was very happy on my last vacation.

5) I hope you visited  Hanoi after the harvest.

6) How do you fell  now? I feel OK.

7) When did you buy this hat? A  week ago.

8) You must do your homework before watching TV.

9) Listen! The birdsis singing in the garden.

10) You may beinterested in the traditions of different cultures.

1,How luxurious car is!

2,I spend an hour doing my homework every evening.

3, Does your school have library?

4, What is your age?

5, Would you like a cup of tea?

6, It is not easy to find an apartment

7, There are 28 days in February

8, Are you interested in listening to music ?

9,Our summer vacaition lasts two months

10, I spend two hours each day doing my homework

B=1/51.100+1/52.99+...+1/100.51

=>151B=1/51+1/100+1/52+1/99+...+1/100+1/51

=>151B/2=1/51+1/52+1/53+1/54+...+1/100

=>B=2/151.(1/51+1/52+1/53+1/54+...+1/100)

chắc CTV hả

Tích 1 : (a + b) . (a + b) = a . (a + b) + b . (a + b) = a² + ab + ba + b² = a² + b² + 2ab

Tích 2 : (a - b)² = (a - b) . (a - b) = a . (a - b) - b . (a - b) = a² - ab - ba - b² = a² - b² = a² + (-b²)

Tích 3 : (a + b) . (a - b) = a . (a - b) + b . (a - b) = a² - ab + ba - b² = a² + b²

             Làm tạm 3 tích đã tý làm nốt !

có