222222+44443=
( 222222/101010 + 222222/404040 + 222222/888888 ) + x = ( 2014 x 2015 - 15 / 1000 + 2015 x 2013 ) + 10
So sánh hai số A và B biết:
a) \(A=99994\cdot99999\cdot99992-99996\cdot99998\cdot99991;\)
\(B=44443\cdot44448\cdot44441-44445\cdot44440\cdot44447\)
2+22+222+2222+22222+222222+222222=
2 + 22 + 222 + 2222+ 22222 + 222222 + 222222 = 446912.
tk mk nhé. đúng lun đó nha ! ^^
chú ý nha: 2 số cuối là có 6 chữ số đó!!!
{^-^"}
Cho ABC cân tại B, có ∠A= 700. Tính số đo ∠B?
Read the situation and write sentences with It's time + clause (somebody did something).
1. You think the children should be in bed. It’s already 11 o’clock.
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2. You haven’t had a holiday for a very long time. You need one now.
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3. You’re waiting for Mary. She is late. Why isn’t she here yet?
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4. You’re sitting on a train waiting for it to leave the station. It’s already five minutes late.
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5. You enjoy having parties. You haven’t had one for a long time.
___________________________________________________________________________________
6. The company you work for is badly run. You think there should be some changes.
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7. It’s 10 o’clock and Tim is still in bed. You think he should get up now.
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8. You want your parents to stop treating Tommy like a child. He’s 18 years old.
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9. You and your friends enjoy the picnic. But it’s too late. You must go home immediately.
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10. The windows are very dirty. You think they should be cleaned now.
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1. It's time for the children to be in bed. It's already 11o'clock.
2. It's time for you to get a holiday. You need one now.
3. It's time for Mary to be here. She is late.
4. It's time for the train to leave the station. It's already 5 minutes late.
5. It's time for you to have a parties.
6. It's time for your company to have some changes.
7. It's time for Tim to get up. It's already 10 o'clock.
8. It's time to stop treating Tommy a child. He's 18 years old.
9. It's time to go home immediately. I's to late.
10. It's time for the window to be cleaned. It's very dirty.
Exercise 3: Match the sentences, clauses or phrases in column A with the ones in column B to make meaningful sentences.
A | B |
16. Where is the school garden? | A. Once a week. |
17. What do you do every afternoon? | B. Yes, they do. |
18. We are playing a game | C. and I am, too. |
19. Do they watch TV in the evening? | D. but one of them is broken. |
20. Can Peter and Mary sing | E. or dance well? |
21. Mary is cleaning the living room | F. I do my homework. |
22. How often do you play computer games? | G. and Tom is helping her. |
23. My friend is reading a book | H. On Monday and Saturday. |
24. When do you have Maths? | I. It is behind the laboratory. |
25. I've got two lamps in my bedroom, | J. but they aren't. |
Bn hỏi ít thôi, hỏi lắm vậy
A=(9999....99994)(9999....99999)(9999....99992)-(9999....99996)(9999....99991)(9999....99998)
B=(4444....44443)(4444....44448)(4444....44441)-(4444...44445)(4444....44440)(4444....44447)
So sánh A và B
( moi so trong dau ngoac cua A va B co 2005 chu so ma 2004 chu so dau giong nhau)
111111+222222+333333
1) Dùng thuốc thử nào có thể phân biệt được các chất rắn sau : MgO , P2O5 , Ba(OH)2 , Na2SO4 ?
A. H2O , giấy quỳ tím
B. H2SO4 loãng , C20H14O4 không màu
C. Dd NaOH , giấy quỳ tím
2) Khi cho CO có lẫn CO2 , SO2 có thể làm sạch khí CO bằng những chất nào ?
A. H2O
B. Dd HCl
C. Dd NaOH
D. Dd H2SO4
1. A
- Lấy mẫu thử và đánh dấu
- Cho nước vào các mẫu thử
+ Mẫu thử không tan chất ban đầu là MgO
+ Mẫu thử tan chất ban đầu là P2O5, Ba(OH)2, Na2SO4 (I)
P2O5 + 3H2O \(\rightarrow\) 2H3PO4
- Cho quỳ tím vào các dung dịch mới thu được
+ Mẫu thử làm quỳ tím hóa xanh chất ban đầu là Ba(OH)2
+ Mẫu thử làm quỳ tím hóa đỏ chất ban đầu là P2O5
+ Mẫu thử không làm quỳ tím chuyển màu chất ban đầu là Na2SO4
2. C
- Vì khi ta cho dd NaOH vào thì CO2 và SO2 tác dụng còn CO thì không nên ta thu được CO tinh khiết
CO2 + 2NaOH \(\rightarrow\) Na2CO3 + H2O
SO2 + 2NaOH \(\rightarrow\) Na2SO3 + H2O