Tính một cách hợp lí:

a) \(\left(3+1\right).\left(3^2+1\right).\left(3^4+1\right).\left(3^8+1\right).\left(3^{16}+1\right)\)

b) \(-1^2+2^2-3^2+4^2-...-99^2+100^2\)

Thực hiện phép nhân:

\(2\frac{1}{315}.\frac{1}{651}-\frac{1}{105}.3\frac{650}{651}-\frac{4}{315.651}+\frac{4}{105}\)

\(\frac{2^7.9^3}{6^5.8^2}=\frac{2^7.\left(3^2\right)^3}{\left(2.3\right)^5.\left(2^3\right)^2}=\frac{2^7.3^6}{2^5.3^5.2^6}=\frac{3}{2^4}=\frac{3}{16}\)

\(\frac{6^3+3.6^2+3^3}{-13}=\frac{\left(3.2\right)^3+3.\left(3.2\right)^2+3^3}{-13}=\frac{3^3.2^3+3.3^2.2^2+3^3}{-13}\)\(=\frac{3^3.\left(2^3+2^2+1\right)}{-13}=\frac{3^3.13}{-13}=-3^3=-27\)

Vẽ OI//AB.

Ta có: OI//AB.

\(\Rightarrow OAB+AOI=180^o\)(2 góc tương ứng).

\(\Rightarrow AOI=180^0-OAB=180^0-120^0=60^0\)

Lại có:

\(QOA=AOI+QOI=140^0\)

\(\Rightarrow QOI=140^0-60^0=80^0\)

Ta thấy:

\(QOI+OQR=80^0+100^0=180^0\)

Mà 2 góc này ở vị trí trong cùng một phía.

\(\Rightarrow\)OI//QR.

Mà OI//AB \(\Rightarrow\) AB//QR.

Cho ví dụ về 4 loại vắc xin phòng bệnh cho lợn ?

Nếu chuồng nuôi thiếu ánh sáng sẽ ảnh hưởng như thế nào đến vật nuôi, đặc biệt là vật nuôi non ?

Rewrite each sentence so it has the same meaning. Use the words in bold.

1. Jane teaches English. (teacher)

=> Jane is an English teacher.

2. There aren't any buses after this one. (last)

=> ..................................................................

3. Have you seen today's paper? (the)

=> ..................................................................

4. English people like tea. (the)

=> ..................................................................

5. Telescopes help you to see things that are far away. (a)

=> ..................................................................

6. Ann is a team-member. (of)

=> ..................................................................

7. The road finishes here. (end of)

=> ..................................................................

8. Tim studies at university. (student)

=> ..................................................................

Bài 19:

1/ Liệt kê những thắng lợi của nghĩa quân Lam Sơn trong trận Chi Lăng – Xương Giang.

2/ Nguyên nhân thắng lợi, ý nghĩa lịch sử.

3/ Cống hiến của Lê Lợi, Nguyễn Trãi đối với sự nghiệp của nước Đại Việt.

Read the passage, answer the questions

Charlie Chaplin was an English actor, director, producer, and composer. He is known as the most creative person of the silent-film era. Charlie Chaplin's portrayal of the tramp won the hearts of people all over the world.
Chaplin was born in London on the 16th of April, 1889. He spent his childhood in poverty and hardship. In 1910 he began to perform pantomime in the United States. He first appeared on screen in 1914. He created his world-famous character, the Tramp, and he played this classic role in more than 70 films during his career. He also composed background music for most of his films. In 1972 Chaplin received an Honorary Academy for 'the incalculable effect he has had in making motion pictures the art form of the century'. Chaplin died on the 25th of December, 1997, at his home in Switzerland.

1. What is Charlie Chaplin famous for?

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

2. What was the art form of this century?

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

3. How was his life during the childhood?

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

4. What was the date of his death?

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

I have made many new friends and I _______ more self-confident.

A. thinks B. have felt C. feel