72^45-72^44=72^44(72-1)=72^44*71

72^44-72^43=72^43(72-1)=72^43*71

=>72^45-72^44>72^44-72^43

a: 199^20=1568239201^5

2003^15=8036054027^5

=>199^20<2003^15

b: 3^99=27^33>27^21=11^21

Lời giải:

a. 

$199^{20}<200^{20}=(2.100)^{20}=2^{20}.10^{40}=(2^{10})^2.10^{40}< (10^4)^2.10^{40}=10^8.10^{40}=10^{48}$
$2003^{15}> 2000^{15}=(2.10^3)^{15}=2^{15}.10^{45}> 2^{10}.10^{45}> 10^3.10^{45}=10^{48}$

$\Rightarrow 199^{20}< 2003^{15}$
b.

$3^{99}=(3^9)^{11}=19683^{11}$
$11^{21}< 11^{22}=(11^2)^{11}=121^{11}$
Hiển nhiên $19683^{11}> 121^{11}$

$\Rightarrow 3^{99}> 121^{11}> 11^{21}$

a: 5^23=5*5^22<6*5^22

=>6*5^22 lớn hơn

b: 7<8

=>7*2^13<8*2^13=2^16

=>2^16 lớn hơn

c: 21^15=3^15*7^15

27^5*49^8=3^15*7^16

mà 15<16

nên 27^5*49^8 lớn hơn

a) Ta có:

5²³ = 5.5²²

Do 6 > 5 nên 6.5²² > 5.5²²

Vậy 6.5²² > 5²³

b) Ta có:

2¹⁶ = 2³.2¹³ = 8.2¹³

Do 8 > 7 nên 8.2¹³ > 7.2¹³

Vậy 2¹⁶ > 7.2¹³

c) Ta có:

21¹⁵ = (3.7)¹⁵ = 3¹⁵.7¹⁵

27⁵.49⁸ = (3³)⁵.(7²)⁸ = 3¹⁵.7¹⁶

Do 16 > 15 nên 7¹⁶ > 7¹⁵

⇒ 3¹⁵.7¹⁶ > 3¹⁵.7¹⁵

Vậy 27⁵.49⁸ > 21¹⁵

\(a.10^{30}=\left(10^3\right)^{10}=1000^{10}\\ 2^{100}=\left(2^{10}\right)^{10}=1024^{10}\)

Vì 1000¹⁰ < 1024¹⁰ => 10³⁰ < 2¹⁰⁰

\(b,333^{444}=\left(111\cdot3\right)^{444}=111^{444}\cdot3^{444}=111^{444}\cdot81^{111}\\ 444^{333}=\left(111\cdot4\right)^{333}=111^{333}\cdot4^{333}=111^{333}\cdot64^{111}\)

Vì 111⁴⁴⁴ >111³³³ ; 81¹¹¹ > 64¹¹¹ => 333⁴⁴⁴ > 444³³³

mình cảm ơn

Ex1: Complete the sentences with: a, an, some, any

        1. We didn’t buy …………flowers.

        2. This evening I’m going out with ………….friends of mine.

        3. “Have you seen ………..good films recently?”

– “No, I haven’t been to the cinema for ages”.

        4. I didn’t have ……………money, so I had to borrow………..

        5. Can I have ………milk in my coffee, please?

        6. I was too tired to do………work.

 7.  There is .................. banana in the basket.

        8. I need ..................tea.

        9. Are there ..................tomatoes in the fridge?

       10. We have .........rice, but we don't have ......meat.

       11. There's ..................orange on the table.

       12. I'd ..................apple juice.

       13. He has ............TV and ............computer.

       14. Would you ..................ice- cream?

       15. I have............... friends in Hue.

       16. Do you have ...............dogs or cats at home?

       17. Would you ..................cup of tea?

       18. I would .................. cakes, please.

       19. Can I have ............glass of milk?

       20. Thank you. And .........box of chocolates would be fine.

       21. I don't have ............... paper.

       22. Is there ............... petrol in the car?

       23. I buy ...............fruit, but I don't have ...............vegetables.

       24. Do you have ............... stamps? I need two.

       25. I need ...............butter to make a cake.

       26. I don't have ...............free time today. Sorry.

       27. Are there............... potatoes in the basket?

        28. There is ...............ink-pot on the table.

EX2: Find and corect the mistakes

Câu 1: How much is a bowl of fried rice?    - They is 2,500 dong.

               A                   B              C                 D

Câu 2: What is you favorite food?

            A       B        C        D

Câu 3: What  weather are you ?  

           A           B       C           D

Câu 4: Are there some books on the table. 

          A                B               C         D

Câu 5: He is going to visits Ngoc Son temple. 

             A         B            C                        D

Câu 6: Are there some books on the table. 

           A              B                C         D

EX3: Complete the sentences with:  “much, many, few, a few, little, a little”

1. He isn’t very popular. He has ………..friends.

2. Ann is very busy these days. She has ………..free time.

3. Did you take …………….photographs when you were on holiday?

4. The museum was very crowded. There were too………..people.

5. Most of the town is modern. There are …………..old buildings.

6. We must be quick. We have………..time.

7. Listen carefully, I’m going to give you ……….advice.

8. Do you mind if I ask you……….questions?

9. This town is not a very interesting place to visit, so …….tourists come here.

10. I don’t think Jill would be a good teacher. She’s got …………..patience.

11. “Would you milk in your coffee?” – “yes, please. ………….”

12. This is a very boring place to live. There’s ………….to do.

Trả lời :

Các số đó là : 510; 1020

# Hok tốt !

\(3^2;2^3\)

\(=9;8\)

\(=3^2>2^3\)

Có đúng ko bạn?

3 mũ 2 thì =9

2 mũ 3 = 8 

mà 9>9

-> 3mu2> 2 mũ 3

3²ⁿ và 2³ⁿ

3²ⁿ = 9ⁿ

2³ⁿ = 8ⁿ

Vì 9ⁿ > 8ⁿ nên 3²ⁿ > 2³ⁿ

3 mũ 99  <  11 mũ 21

mình nghĩ    11 mũ 21 < 3 mũ 99

nhầm mà

3⁹⁹ < 11²¹

Ta có:

\(\frac{2}{5}=\frac{8}{20};\frac{4}{2}=\frac{40}{20};\frac{6}{2}=\frac{60}{20};\frac{9}{4}=\frac{45}{20};\frac{5}{4}=\frac{25}{20}\)

Vì \(\frac{8}{20}

8/20 nhaaaaaaaaaaa

8/20 nha

5³⁰⁰ = (5²)¹⁵⁰ = 25¹⁵⁰

3⁴⁵³ > 3⁴⁵⁰ = (3³)¹⁵⁰ = 27¹⁵⁰

Vì 25¹⁵⁰ < 27¹²⁰

=> 5³⁰⁰ < 3⁴⁵³

Ủng hộ mk nha ^_-

cảm ơn soyeon_Tiểu bàng giải nhiều

\(5^{300}\)<  \(3^{453}\)

a) \(3\sqrt[3]{2}=\sqrt[3]{3^3.2}=\sqrt[3]{54}>\sqrt[3]{53}\)

b) \(22=\sqrt[3]{22^3}=\sqrt[3]{10648}>\sqrt[3]{10638}=3\sqrt[3]{394}\)