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28 tháng 9 2016

3^2n>2^3n

23 tháng 10 2020

\(\hept{\begin{cases}3^{2n}=9^n\\2^{3n}=8^n\end{cases}}\)

nếu n=0\(\Rightarrow\hept{\begin{cases}9^n=9^0=1\\8^n=8^0=1\end{cases}\Rightarrow9^n=8^n}\)

nếu n>0\(\Rightarrow9^n>8^n\)

vậy \(3^{2n}\ge2^{3n}\)

có ai biết làm bài này không giúp mình với ( xin cảm ơn)viết hình thức so sánh hơn và nhất của các tính từ sau:ADJ/advHơnNhấtADJ/advHơnNhất1- cheapcheaperThe cheapest7- friendly................................................2- far...........................................8- badly/bad................................................3- big..........................................9- many/much................................................4-...
Đọc tiếp

có ai biết làm bài này không giúp mình với ( xin cảm ơn)

viết hình thức so sánh hơn và nhất của các tính từ sau:

ADJ/adv

Hơn

Nhất

ADJ/adv

Hơn

Nhất

1- cheap

cheaper

The cheapest

7- friendly

........................

........................

2- far

.....................

......................

8- badly/bad

........................

........................

3- big

......................

....................

9- many/much

........................

........................

4- fluent

......................

.....................

10- dangerous

........................

........................

5- good/well

......................

.....................

11- hard

........................

........................

6- busy

.....................

.....................

12- quiet

........................

........................

1. So sánh ngang bằng.

a. This book/ not/ interesting/ I expected

_______________________________________________

b. Jack/ swim/ good/ Tom

_______________________________________________

c. we/work/twice/slow/ they.

_______________________________________________

d. A car/ not/run/ fast/ a train

_______________________________________________

e. My father/ carve /skilful/ my grandfather

_______________________________________________

2. So sánh hơn: (Nhấn mạnh các câu ss hơn)

a. My room/ comfortable/ yours

_______________________________________________

b. A plane/can fly/ quick/ a bird

_______________________________________________

c. Peter/ eat/ much/ I.

_______________________________________________

d .Your house/far/from school /my house. _______________________________________________

e. My father / cook/ good/ I

_______________________________________________

3. So sánh nhất: ( Nhấn mạnh theo 2 cách đã học)

a. Everest/ high/ mountion/ in the world

_______________________________________________

b. Mai/ talk/ slow / in my class.

_______________________________________________

c. English coffee/bad/ of all.

_______________________________________________

d. Anna/ behave/polite/ in the world.

_______________________________________________

e. They / play the guitar/ good/ of all

._______________________________________________

f. My grandmother/old/ in my village=>

_______________________________________________

II. Complete the sentences using the correct form of the adjectives or adverbs in brackets

(chia về các dạng so sánh đúng)

III. Cirle the best option to complete each sentence:

1. The flower was.......... out of a single piece of valuable wood. 

A. carved              B. moulded       

C cast                   D. given

2. In this town, they_____ all the frames in steel.

A. make               B. have                     C. mould                    D. cast

3. She is skilled at ____ cloth.

A. giving               B. weaving                C doing                      D. carving 

4. If you like, I can_____ flowers on the cushion covers for you.

A. grow                B. make                    C. embroider               D. knit

5. Is it true that you.......... this woollen hat yourself?

A. knitted             B. wove                    C did                          D. carved

6. The doll has been.......... out of clay.

A. embroidered      B. cast                    C. woven                  D. moulded

7. I love going to this place _____ it's the quietest place in the city.

A. so                     B. though                  C. so that              D. as 

8. They keep changing the decoration of the shop_______ they can attract more young people.

A. so that              B. because                C. although           D when

9.________ he's young, she's the most famous artisan in the village.

A. When                B. Although                C. Whereas           D. In order to

10. Do you know who's______ his pottery workshop?

A. bring out           B. taking over            C. passing down    D. turning down

11. I've_______ the product catalogue and decided to buy this table.

A. found out          B. closed down            C. looked through   D. lived on

12. This sports centre is so small that it cannot______the demands of local residents.

A. keep up with        B. face up to            C. deal about            D. setup

13. When I turned up, the town hall was already_____ of teenagers.

A. full                   B. packed     C. crowded           D. jammed

14. She turned ______the new job in New York because she didn't want to move.

 

4. This laptop is much more user-friendly, but it costs________ the other one.

A. so much as                  B. as many as     C. twice as much as         D. twice as many

5. Today's cities are____than cities in previous times.

A. lots larger                  B. much larger    C. as large                     D. the largest

6. After I found all the information I needed, I________the computer.

 A. turned off                 B. switched on    C. looked for                  D. put off

7. Japan is the__________ developed country in the world.

A. most second             B. second in most        C. second most             D. two most

8. Factories and offices should be built in __________areas only.

A. rural                        B. Coastal      C. culture                     D. urban

 

0
22 tháng 2 2016

huhu trả lời dùm mik đi mai mik phải nộp rồi :'9

ai có thể giúp mình làm bài này với đc không ạ (xin cảm ơn)I.Hãy viết hình thức so sánh hơn và nhất của các tính từ sau:ADJ/advHơnNhấtADJ/advHơnNhất1- cheapcheaperThe cheapest7- friendly................................................2- far...........................................8- badly/bad................................................3- big..........................................9- many/much................................................4-...
Đọc tiếp

ai có thể giúp mình làm bài này với đc không ạ (xin cảm ơn)

I.Hãy viết hình thức so sánh hơn và nhất của các tính từ sau:

ADJ/adv

Hơn

Nhất

ADJ/adv

Hơn

Nhất

1- cheap

cheaper

The cheapest

7- friendly

........................

........................

2- far

.....................

......................

8- badly/bad

........................

........................

3- big

......................

....................

9- many/much

........................

........................

4- fluent

......................

.....................

10- dangerous

........................

........................

5- good/well

......................

.....................

11- hard

........................

........................

6- busy

.....................

.....................

12- quiet

........................

........................

1. So sánh ngang bằng.

a. This book/ not/ interesting/ I expected

_______________________________________________

b. Jack/ swim/ good/ Tom

_______________________________________________

c. we/work/twice/slow/ they.

_______________________________________________

d. A car/ not/run/ fast/ a train

_______________________________________________

e. My father/ carve /skilful/ my grandfather

_______________________________________________

2. So sánh hơn: (Nhấn mạnh các câu ss hơn)

a. My room/ comfortable/ yours

_______________________________________________

b. A plane/can fly/ quick/ a bird

_______________________________________________

c. Peter/ eat/ much/ I.

_______________________________________________

d .Your house/far/from school /my house. _______________________________________________

e. My father / cook/ good/ I

_______________________________________________

3. So sánh nhất: ( Nhấn mạnh theo 2 cách đã học)

a. Everest/ high/ mountion/ in the world

_______________________________________________

b. Mai/ talk/ slow / in my class.

_______________________________________________

c. English coffee/bad/ of all.

_______________________________________________

d. Anna/ behave/polite/ in the world.

_______________________________________________

e. They / play the guitar/ good/ of all

._______________________________________________

f. My grandmother/old/ in my village=>

_______________________________________________

II. Complete the sentences using the correct form of the adjectives or adverbs in brackets

(chia về các dạng so sánh đúng)

III. Cirle the best option to complete each sentence:

1. The flower was.......... out of a single piece of valuable wood. 

A. carved              B. moulded       

C cast                   D. given

2. In this town, they_____ all the frames in steel.

A. make               B. have                     C. mould                    D. cast

3. She is skilled at ____ cloth.

A. giving               B. weaving                C doing                      D. carving 

4. If you like, I can_____ flowers on the cushion covers for you.

A. grow                B. make                    C. embroider               D. knit

5. Is it true that you.......... this woollen hat yourself?

A. knitted             B. wove                    C did                          D. carved

6. The doll has been.......... out of clay.

A. embroidered      B. cast                    C. woven                  D. moulded

7. I love going to this place _____ it's the quietest place in the city.

A. so                     B. though                  C. so that              D. as 

8. They keep changing the decoration of the shop_______ they can attract more young people.

A. so that              B. because                C. although           D when

9.________ he's young, she's the most famous artisan in the village.

A. When                B. Although                C. Whereas           D. In order to

10. Do you know who's______ his pottery workshop?

A. bring out           B. taking over            C. passing down    D. turning down

11. I've_______ the product catalogue and decided to buy this table.

A. found out          B. closed down            C. looked through   D. lived on

12. This sports centre is so small that it cannot______the demands of local residents.

A. keep up with        B. face up to            C. deal about            D. setup

13. When I turned up, the town hall was already_____ of teenagers.

A. full                   B. packed     C. crowded           D. jammed

14. She turned ______the new job in New York because she didn't want to move.

A. on                   B. down  C. off                   D. up

15. This city has one of the most___ underground rail networks in the world.

A. efficient                           B. fashionable   C . cosmopolitan                   D. fascinated

4. This laptop is much more user-friendly, but it costs________ the other one.

A. so much as                  B. as many as     C. twice as much as         D. twice as many

5. Today's cities are____than cities in previous times.

A. lots larger                  B. much larger    C. as large                     D. the largest

6. After I found all the information I needed, I________the computer.

 A. turned off                 B. switched on    C. looked for                  D. put off

7. Japan is the__________ developed country in the world.

A. most second             B. second in most        C. second most             D. two most

8. Factories and offices should be built in __________areas only.

A. rural                        B. Coastal      C. culture                     D. urban

0
5 tháng 8 2021

22,

1, Đặt √(3-√5) = A

=> √2A=√(6-2√5)

=> √2A=√(5-2√5+1)

=> √2A=|√5 -1|

=> A=\(\dfrac{\sqrt{5}-1}{\text{√2}}\)

=> A= \(\dfrac{\sqrt{10}-\sqrt{2}}{2}\)

2, Đặt √(7+3√5) = B

=> √2B=√(14+6√5)

 => √2B=√(9+2√45+5)

=> √2B=|3+√5|

=> B= \(\dfrac{3+\sqrt{5}}{\sqrt{2}}\)

=> B= \(\dfrac{3\sqrt{2}+\sqrt{10}}{2}\)

3, 

Đặt √(9+√17) - √(9-√17) -\(\sqrt{2}\)=C

=> √2C=√(18+2√17) - √(18-2√17) -\(2\)

=> √2C=√(17+2√17+1) - √(17-2√17+1) -\(2\)

=> √2C=√17+1- √17+1 -\(2\)

=> √2C=0

=> C=0

26,

|3-2x|=2\(\sqrt{5}\)

TH1: 3-2x ≥ 0 ⇔ x≤\(\dfrac{-3}{2}\)

3-2x=2\(\sqrt{5}\)

-2x=2\(\sqrt{5}\) -3

x=\(\dfrac{3-2\sqrt{5}}{2}\) (KTMĐK)

TH2: 3-2x < 0 ⇔ x>\(\dfrac{-3}{2}\)

3-2x=-2\(\sqrt{5}\)

-2x=-2√5 -3

x=\(\dfrac{3+2\sqrt{5}}{2}\) (TMĐK)

Vậy x=\(\dfrac{3+2\sqrt{5}}{2}\)

 

 

 

 

 

 

6 tháng 8 2021

2, \(\sqrt{x^2}\)=12 ⇔ |x|=12 ⇔ x=12, -12

3, \(\sqrt{x^2-2x+1}\)=7

⇔ |x-1|=7 

TH1: x-1≥0 ⇔ x≥1

x-1=7 ⇔ x=8 (TMĐK)

TH2: x-1<0 ⇔ x<1

x-1=-7 ⇔ x=-6 (TMĐK)

Vậy x=8, -6

4, \(\sqrt{\left(x-1\right)^2}\)=x+3

⇔ |x-1|=x+3

TH1: x-1≥0 ⇔ x≥1

x-1=x+3 ⇔ 0x=4 (KTM)

TH2: x-1<0 ⇔ x<1

x-1=-x-3 ⇔ 2x=-2 ⇔x=-1 (TMĐK)

Vậy x=-1