1,The most historic

2,The most convenient

3,The most beautiful

4,boriest

5,The most polluted

6,prettiest

7,nicest

8,The most impressive

9,The most intelligent

10,The most expensive

thêm most vào trước

a,young hoặc new (chọn cái nào cũng đc)

b,modern 

c,narrow

d,interesting (exciting)

e,quiet

f,inconvinient

g,decontaminated

h,expensive

i,unfriendly

j,ugly

k,short

l,uncomfortale

m,big

n,noisy(unpeaceful)

o,dry

p,cold

$C=1+4+...+4^{6}$

$4C=4+4^{2}+...+4^{7}$

$4C-C=4+4^{2}+...+4^{7}-1-4-...-4^{6}$

$3C=4^{7}-1$

$C=\dfrac{4^{7}-1}{3}$

Để tính tổng S = 1 + 4 + 4^2 + ... + 4^6, ta có thể sử dụng công thức tổng của cấp số nhân:

S = (a * (r^n - 1)) / (r - 1)

Trong đó:
- a là số hạng đầu tiên của dãy (a = 1)
- r là công bội của dãy (r = 4)
- n là số lượng số hạng trong dãy (n = 6)

Áp dụng vào bài toán, ta có:

S = (1 * (4^6 - 1)) / (4 - 1)
= (4^6 - 1) / 3

Để chứng minh A = {(4^7 - 1) : 3}, ta cần chứng minh rằng S = (4^7 - 1) : 3.

Ta có:
(4^7 - 1) : 3 = (4^7 - 1) / 3

Để chứng minh hai biểu thức trên bằng nhau, ta sẽ chứng minh rằng (4^7 - 1) / 3 = (4^6 - 1) / 3.

Ta có:
(4^7 - 1) / 3 = (4^6 * 4 - 1) / 3
= (4^6 * 4 - 1 * 4^0) / 3
= (4^6 * 4 - 4^6) / 3
= 4^6 * (4 - 1) / 3
= (4^6 - 1) / 3

Vậy ta đã chứng minh được A = {(4^7 - 1) : 3}.

5/s hay là5,s vậy

S = 1 + 2 + 2² + 2³ +2⁴ + 2⁵ +...+ 2⁶⁰ + 2⁶¹ + 2⁶² + 2⁶³

   = ( 1 + 2²) +( 2 + 2³) + (2⁴ + 2⁶) + ( 2⁵ + 2⁷) +...+ (2⁶⁰ + 2⁶²) + ( 2⁶¹ + 2⁶³)

   =( 1 + 2²) + 2 ( 1 + 2²) + 2⁴ (1 + 2²) + 2⁵ (1 +2²)+...+ 2⁶⁰ ( 1 + 2²) + 2⁶¹( 1 + 2²)

   = ( 1 + 2²)( 1 + 2 +2⁴ + 2⁵ +...+ 2⁶⁰)

   =  5 ( 1 + 2 +2⁴ + 2⁵ +...+ 2⁶⁰) 

Vậy S chia hết cho 5 vì có một thừa số là 5.

xin lỗi bạn nhé Thu Hà , mình nhấn nhầm tích, mình cảm ơn bạn nha, để câu hỏi khác mình k cho bạn nhé , thành thật xin lõi bạn

Câu này á ???

Bài 2 :

\(B=2014\cdot2020\)

\(B=\left(2017-3\right)\left(2017+3\right)\)

\(B=2017^2-3^2\)

\(B=2017^2-9< A=2017^2\)

Vậy \(B< A\)

\(B=2014.2020\)

\(B=\left(2017-3\right)\left(2017+3\right)\)

\(B=\left(2017-3\right).2017+\left(2017+3\right).3\)

\(B=2017^2-3.2017+2017.3+3^2\)

\(B=2017^2-3^2< 2017^2=A\)

  Vậy A > B

   _Hok tốt_

!!!

hello my name is science, 6d grade intelligent, intelligent 12-year-old middle school thcs bar, tea and shakes his loyal py in Thai Nguyen

on every morning I usually teach from 6 hours, then go get dressed, brush your teeth, wash your face, then eat breakfast, go to school. Afternoon often helps her parents with housework and homework, his hobby is eating fried chicken, cake, and then go out with their parents. on his summer days often parents for a swim, go fishing there like her very often at his winter home and go to bed very early, I like to play sports as jumping rope, badminton, confused .

hello my name is science , 6d grade intelligent , intelligent 12 -year-old middle school thcs bar , tea and shakes his loyal py in Thai Nguyen on every morning I usually teach from 6 hours , then go get dressed , brush your teeth , wash your face , then eat breakfast , go to school . Afternoon often helps her parents with housework and homework, his hobby is eating fried chicken , cake , and then go out with their parents. on his summer days often parents for a swim , go fishing there like her very often at his winter home and go to bed very early, I like to play sports as jumping rope , badminton , confused .

còn bài nào k bài này dễ quá