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Những câu hỏi liên quan
Violet
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Đỗ Thanh Hải
29 tháng 6 2021 lúc 10:11

53 Are there 800 pupils in you school?

53 There are 6 children in your family

55 How much do a cack and an orange cost?

57 How much does a bottle of cooking oil cost

59 My father is going to Ha Noi by car 

60 Nam's father has a white car

61 How much beef would you like

63 I go to school by bicycle everyday

65 Phong's sister is nhung

67 Trung is Mr Minh's son

68 Huyen goes to school on foot...

69Nam is Phuong's brother

Violet
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Komorebi
30 tháng 6 2021 lúc 17:29

I'm going to visit Mui Ne this summer.

Đỗ Thanh Hải
30 tháng 6 2021 lúc 17:29

I'm going to visit Mui Ne this summer

Violet
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Khinh Yên
5 tháng 7 2021 lúc 16:10

use

is jane watching

doesn't go

is ating

do you study

am not listening- am playing

is raining- rains

are reading

am often playing=>often plays

is wanting=>wants

doesn't =>don't

have=>are having

skip=>skipping

is having=>has

cook =>am cooking

 

minh nguyet
5 tháng 7 2021 lúc 16:11

IV,

1. use

2. Is Jane watching...?

3. doesn't go

4. is eating

5. Do you sutdy...?

6. amn't listening... am playing

7. is going to rain... rains

8. are reading

V,

1. playing=> play

2. is wanting=> want

3. doesn't=> don't

4. have=> are having

5. skip=> skipping

6. is having=> has

7. cook=> am cooking

Nguyễn Việt Lâm
14 tháng 9 2021 lúc 19:19

c.

ĐKXĐ: \(sinx\ne0\Rightarrow x\ne k\pi\)

\(1-\dfrac{\sqrt{3}cosx}{sinx}-4cosx=0\)

\(\Rightarrow sinx-\sqrt{3}cosx-4sinx.cosx=0\)

\(\Leftrightarrow sinx-\sqrt{3}cosx=2sin2x\)

\(\Leftrightarrow\dfrac{1}{2}sinx-\dfrac{\sqrt{3}}{2}cosx=sin2x\)

\(\Leftrightarrow sin2x=sin\left(x-\dfrac{\pi}{3}\right)\)

\(\Leftrightarrow\left[{}\begin{matrix}2x=x-\dfrac{\pi}{3}+k2\pi\\2x=\dfrac{4\pi}{3}-x+k2\pi\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{\pi}{3}+k2\pi\\x=\dfrac{4\pi}{9}+\dfrac{k2\pi}{3}\end{matrix}\right.\)

Nguyễn Việt Lâm
14 tháng 9 2021 lúc 19:14

a.

\(\Leftrightarrow3sin3x-4sin^34x-\sqrt{3}cos9x=2sin2x\)

\(\Leftrightarrow sin9x-\sqrt{3}cos9x=2sin2x\)

\(\Leftrightarrow\dfrac{1}{2}sin9x-\dfrac{\sqrt{3}}{2}cos9x=sin2x\)

\(\Leftrightarrow sin\left(9x-\dfrac{\pi}{3}\right)=sin2x\)

\(\Leftrightarrow\left[{}\begin{matrix}9x-\dfrac{\pi}{3}=2x+k2\pi\\9x-\dfrac{\pi}{3}=\pi-2x+k2\pi\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{\pi}{21}+\dfrac{k2\pi}{7}\\x=\dfrac{4\pi}{33}+\dfrac{k2\pi}{11}\end{matrix}\right.\)

Nguyễn Việt Lâm
14 tháng 9 2021 lúc 19:17

b.

\(\Leftrightarrow\sqrt{3}cosx+sin3x-sinx-sin3x=\sqrt{2}\)

\(\Leftrightarrow\sqrt{3}cosx-sinx=\sqrt{2}\)

\(\Leftrightarrow\dfrac{\sqrt{3}}{2}cosx-\dfrac{1}{2}sinx=\dfrac{\sqrt{2}}{2}\)

\(\Leftrightarrow cos\left(x+\dfrac{\pi}{6}\right)=cos\left(\dfrac{\pi}{4}\right)\)

\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{\pi}{6}=\dfrac{\pi}{4}+k2\pi\\x+\dfrac{\pi}{6}=-\dfrac{\pi}{4}+k2\pi\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{\pi}{12}+k2\pi\\x=-\dfrac{5\pi}{12}+k2\pi\end{matrix}\right.\)

Hoàng Ngân Hà
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Hoàng Ngân Hà
27 tháng 1 2022 lúc 19:10

Help mik đi mik tick cho

Nguyễn Ngọc Khánh Huyền
27 tháng 1 2022 lúc 19:10

\(\dfrac{2}{7}=\dfrac{10}{35}=\dfrac{12}{42}=\dfrac{16}{56}\)

Nguyễn Lê Phước Thịnh
27 tháng 1 2022 lúc 19:11

2/7=10/35=12/42=16/56

Khánhh
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Tryechun🥶
27 tháng 4 2022 lúc 8:02

đề :)?

Thế Quốc
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Ami Mizuno
24 tháng 7 2021 lúc 8:17

2.A

Ami Mizuno
24 tháng 7 2021 lúc 8:18

3.A

Khương Gia Bình
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