a: \(=27a^3+27a^2+9a+1\)

b: \(=64-96b+48b^2-8b^3\)

c: \(=8c^3+36c^2d+54cd^2+27d^3\)

\(=\left(x-x\right)^2+\left(y-y\right)^2=0^2+0^2=1+1=2\)

\(x^2-x-y^2-y\)

\(=\left(x^2-y^2\right)-\left(x+y\right)\)

\(=\left(x-y\right)\left(x+y\right)-\left(x+y\right)\)

\(=\left(x+y\right)\left(x-y-1\right)\)

Tham khảo link :   https://engbreaking.com/bai-luan-tieng-anh/

Giới thiệu: - Giới thiệu chủ đề.

- Đưa ra thông tin cơ bản và Thu hẹp chủ đề.

- Đưa ra quan điểm của bạn và đề cập đến các lĩnh vực chính được đề cập trong bài luận.

Thân hình: Phân tích quan điểm 

Phần kết luận: - Hãy khôi phục lại quan điểm của bạn.

- Tóm tắt là bắt buộc.

a)Ta có: AC<AB

=>\(\widehat{ADC}\)<\(\widehat{ADB}\)

b)

\(x^2-2xy-4z^2+y^2\)

\(=\left(x^2-2xy+y^2\right)-4z^2\)

\(=\left(x-y\right)^2-\left(2z\right)^2\)

\(=\left(x-y-2z\right)\left(x-y+2z\right)\)

Thay ............... :

 \(\left(\left(-4\right)-y-2.45\right)\left(\left(-4\right)-y+2.45\right)\)

\(=\left(-y-49\right)\left(86-y\right)\)

????????

1. How do you learn English?

I learn English well

2. What can do you to help the community?

I can help the community help for the elderly, disabled children

To understand deeply a culture, you must know how to speak its language. It is true that English has become the international language in business, airline and communication. If we know English, we can communicate and read books in English. We can learn and understand more about the modern technology and science from countries all over the world. I think it is very useful for us to learn English well.
How to learn English well? It’s a hard question for many students. There are many ways of learning English. And today I want to tell about my experience of learning English.

I have learned English for 5 years from primary school to now, and I learned both at school and at home. At school, if I don't understand anything, I will ask my teacher or my friends. At home, I often do more grammar exercises in grammar books or use Internet to search new exercises.

Besides, we can learn English by other ways. I always learn structures by heart and make sentences with structures. Now my writing and speaking is quite good but my listening is bad. So I speak English with my friends regularly. I learn by heart all the new words, write English words as much as possible, watch TV programs, listen to English tapes or English programs on the radio, read short stories or newspapers in English, use a dictionary to look up new words, etc…

And that is my ways to learn English. I think we should try different ways to find the most suitable one for us. And I hope every student in my school will study English well.

Các biện pháp phòng chống giun đũa kí sinh ở người là:

+ Giữ vệ sinh môi trường

+ Vệ sinh cá nhân khi ăn uống

+ Tẩy giun định kì 6 tháng 1 lần