a)A=(2x+y)²-(y-2x)²

\(A=(2x+y-y+2x)(2x+y+y-2x)\)

\(A=4x.2y=8xy\)

b)B=x²-y²+(x-y)²

\(B=x^2-y^2+x^2-2xy+y^2\)

\(B=2x^2-2xy\)

Lần sau bạn đăng vào môn Toán nhé!!!

1.  you/ have/ an art lesson on Monday (no)

    _Do you have an art lesson on Monday? 
no, I don't 

2.  they/ ride/ their bikes to school (yes)

Do they ride their bikes to school?

yes, they do 

3.  Jane/ play/ tennis at school (no)

     _____does Jane play tennis at school_______________________ ?______No, he isn't _____________

4.  your parents/ at home now (yes)

    Are your parents at home now__________ ?_____yes , they are________

5.  he/ have/ breakfast at 6 o’clock every day (yes)

  does he have breakfast at 6 o'clock every day___ ?_________yes, he does__________

6.  you/ a good student (no)

    Are you a good student___________ ?_______No, I am not ____________

7.  I/ look/ well (no)

  Do You look well__ ?___No, I don't ___________

8.  Ms. Van/ a good teacher (yes)

    Is Ms. Van a good teacher_____ ? Yes, she is

Ko có dấu bằng kìa bạn

Mình nhầm trùng giày và trùng roi nhé

Bạn đúng r đấy

1. I usually (go) __go______ to school by bike.

2. They often (visit) ____visit____ us at weekends.

3. He usually (play) ___plays_____ badminton in the afternoon.

4. I (drink) ___drink_____ bubble tea three times a week.

5. She always (buy) _____buys___ flowers on Monday.

6. The students (not have) ____don't have____ English on Thursday.

7. They (not open) _____don't open___ the store at 7 a.m.

8. Lily (be) ___is____ a pretty girl.

9. He (live) _____lives___ in a big apartment.

10. Alex (go) ____goes____ to the library twice a week.

11. She (not speak) ___doesn't speak_____ English fluently.

12. My grandmother (have) _____has___ a beautiful garden.

13. Hanoi (be) ____is____ the capital of Vietnam.

14. My father always (watch) ___watches_____ the news in the evening.

15. He (study) _studies_______ English every day.

16. What (you/ do) ____Do you do____ in your free time?

17. Autumn (not be) __isn't____ the hottest season of the year.

18. (he/ do) ___does he do_____ morning exercise every day?

19. My teacher (teach) __teaches______ me how to make models.

20. How (she/ go) __does she go______ to school?