Dùng quy tắc đổi dấu, hãy điền đa thức thích hợp vào chỗ trống để được đẳng thức:  x - y 2 y - x   =   y - x   . . .

A. 2y- x     

B. x – 2y 

C. 2y + x     

D. – 2y – x 

Lũ quét thường xảy ra ở miền núi không phải do

A. Địa hình bị chia cắt mạnh

B. mất lớp phủ thực vật

C. Địa hình có độ dốc lớn

D. sử dụng đất không hợp lí

Is there a new shopping mall in the neighborhood going to be built next year?

5. does -> do

6. help -> helping

7. think -> thinking ( always + V_ing: một thói quen làm người khác khó chịu)

2. This is the first time I ate this kind of food.
3. it has started raining for an hour
4. The last time we have visited my grandparents was two months ago.
5. I began studying English three years ago.
6. It's nearly five years since my brother last saw his best friend.
7. How long have you learned English?
9. Those houses are more larger than there houses.
10. My packback is different from your packback
11. Ba has collected stamps for three years.
12. We have lived here for twenty years.
13. I haven't seen Nam for five years.
14. She hasn't visited us for four months.
15. I have met Susan since 2006.
16. Minh has had a digital camera since 2001.
17. Mai has played the piano since she was ten years old.
18. Babara has arrived to Hanoi for five months.
19. They have lived here for a month.
20. My shoes are not the same as yours.

câu hỏi mất dạy

B

X^3/8=x/2

Y^3/64=y/4

Z^3/216=z/6

=> x^2/4

=y^2/16

=z^2/36

=> x^2+y^2+z^2/4+16+36

=>14/56=1/4

=> x,y,z