Đây là dãy số lẻ liên tiếp 

=> số số hạng là:

(99-23):2+1=?

tổng là:

(99+23).?:2

23 + 25 + 27 + 29 + .......... + 99

Số số hạng là:

(99 - 23) : 2 + 1 = 39

Tổng dãy trên là:

 (99 + 23) . 39 + 1 = 4759

Chúc bạn học tốt!

a) 63¹⁹ > 3⁷⁶

b) 3⁴⁵ < 123¹⁰

Học tốt!!!

a, 3^76=(3^4)^19=81^19

vay 63^19<3^76

b, TA co :

3^45=(3^9)^5

123^10=(123^2)^5

Ta so sanh 123^2 va 3^9

3^9=(3^3)^3=27^3=27*27*27

123^2=(3^2)*(21^2)=9.21*21

suy ra 3^45>123^10

Đây ạ em vái olm đùng có như câu trước nx ạ

It will be a great joy or happiness for everyone if we can own a house designed by ourselves. A house in my dream is not necessarily a large house, as long as it fits my style and character. A house located on the outskirts of town will be very suitable for me to enjoy a serene life. It will be a two- storey house facing west-south side. Moreover, my house can not be lack of a large garden surrounded by thousands of different colors of flowers and fruits. I it the most when having a breakfast or enjoying night views in my own garden. Simplicity is beauty, this explains why I would prefer an airy space rather than a well- equipped house. However, the house should have basic necessities in the kitchen and bathroom to serve all my demands in daily life. In addition, I will use bright color tones for the whole house, especially my bedroom to make it more spacious. My bedroom will be more perfect and ideal if it has a balcony where i could smell the fragrance from the garden as well as enjoy the sound of the birds in the morning. Besides, I also have an intention of having a small garage and storage. In conclusion, nothing but a suitable house for my lifestyles will fulfill my future dream.

My dream house is a large villa. It is near the coast, surrounded by rows of coconut trees and the blue sea. There are sixteen rooms in my house and half of them for relaxation and entertainment. It has a big garage so that I can store my super cars there. My house has wind power or solar energy. I use hi-tech and automa machines such as a smart clock, modern fridge, automa dishwasher and washing machine. They can be controlled by voice and help me tell the time, forecast weather, preserve food and wash dishes and clothes. There is a super smart TV in my house. I might surf the internet, watch my favourite TV programmes from space or contact friends on other planets by this fantas TV. I might also join online classes on TV and not have to go to school.

a)đi thưa, về chào, vầng lời cha mẹ, ông bà, ngoan ngoãn , lễ phép

b)đi học đúng giờ, tôn trọng bạn bè, lễ phép với thầy cô giáo, học bài , làm bài đầy đủ

c) tôn trọng mọi người , chào hỏi những người quen ,

(mình hông bít đúng hay sao nữa.hihi)

a (12 - 8) : 4 = 1

b) 12 . (4 + 2) -12 = 60

c) (4 + 8) . 5 - 4 . 5 = 40

d) 10 : (5 + 5) . 9 . 9 = 81

Ko có công thức trừ 1 lũy thừa , muốn trừ thì tính cụ thể 2 lũy thừa ra rồi trừ

Chỉ có nhân và chia thôi ko có trừ đâu bạn

nhân:a^m . aⁿ = a^m+n

chia:a^m : aⁿ = a^m-n

(2^x-11)⁷=(2^x-11)⁵

\(\Rightarrow\hept{\begin{cases}2^x-11=1\\2^x-11=-1\\2^x-11=0\end{cases}\Rightarrow\hept{\begin{cases}2^x=12\\2^x=10\\2^x=11\end{cases}\Rightarrow}x\in\varnothing}\)

Vậy ko tìm đc g/trị của x

A=1+2+2^2+2^3+...+2^100

2A=2+2^2+2^3+...+2^101

2A - A=A=( 2+2^2+2^3+...+2^101 )-(1+2+2^2+2^3+...+2^100)

ta lần lượt gạch đi các số hạng giống nhau ở mỗi vế;suy ra A=2^101-1

Ta có

\(63^{19}=(3^2)^{19}.7^{19}=3^{38}.7^{19}\)

\(3^{76}=3^{38}.9^{19}\) 

Bạn tự so sánh nha!

\(3^{45}=3^{10}.3^{35}=3^{10}.(3^7)^5=3^{10}.2187^5\)

\(123^{10}=3^{10}.41^{10}=3^{10}.(41^2)^5=3^{10}.1681^5\)

\(\Rightarrow 3^{45}>123^{10}\)