P={\(\dfrac{2}{3};\dfrac{2}{4};\dfrac{3}{2};\dfrac{3}{4};\dfrac{4}{2};\dfrac{4}{3}\)}

Lm đc bài tổng quát này thì ok: So sánh: \(\dfrac{1}{a^b}\)và\(\dfrac{1}{b^a}\) bik a>b

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

         Today, roller skating is easy and fun. But a long time ago, it wasn't easy at all. Before 1750, the idea of skating didn't exist. That changed because of a man named Joseph Merlin. Merlin's work was making musical instruments. In his spare time he liked to play the violin. Joseph Merlin was a man of ideas and dreams. People called him a dreamer.

         One day Merlin received an invitation to attend a fancy dress ball. He was very pleased and a little excited. As the day of the party came near, Merlin began to think how to make a grand entrance at the party. He had an idea. He thought he would get a lot of attention if he could skate into the room.

Merlin tried different ways to make himself roll. Finally, he decided to put two wheels under each shoe. These were the first roller skates. Merlin was very proud of his invention as he dreamed of arriving at the party on wheels while playing the violin.

          On the night of the party Merlin rolled into the room playing his violin. Everyone was astonished to see him. There was just one problem. Merlin had no way to stop his roller skates. He rolled on and on. Suddenly, he ran into a huge mirror that was hanging on the wall. Down fell the mirror, breaking to pieces. Nobody forgot Merlin's grand entrance for a long time!

People thought Merlin was a dreamer because he ___________.

A. was a gifted musician

B. invented the roller skates

C. often gave others surprises

D. was full of imagination

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions

People believed that Jane retired because of her poor health

A. Jane is believed to have retired because of her poor health

B. Jane was believed to have retired because of her poor health

C. It is believed that Jane retired because of her poor health.

D. Jane retired because of her poor health was believed

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 45 to 54.

Colors are one of the most exciting experiences in life. I love them, and they are just as important to me as emotions are. Have you ever wondered how the two are so intimately related? Color directly affects your emotions. Color both reflects the current state of your emotions, and is something that you can use to improve or change your emotions. The color that you choose to wear either reflects your current state of being, or reflects the color or emotion that you need.

The colors that you wear affect you much more than they affect the people around you. Of course, they also affect anyone who comes in contract with you, but you are the one saturated with the color all day! I even choose items around me based on their color. In the morning, I choose my clothes based on the color or emotion that I need for the day. So you can consciously use color to control the emotions that you are exposed to, which can help you to feel better.

Color, sound, and emotions are all vibrations. Emotions are literally energy in motion; they are meant to move and flow. This is the reason that real feelings are the fastest way to get your energy in motion. Also, flowing energy is exactly what creates healthy cells in your body. So, the fastest way to be healthy is to be open to your real feelings. Alternately, the fastest way to create disease is to inhibit your emotions

Why does the author mention that color and emotions are both vibrations?

A. Because they both affect how we feel

B. To show how color can affect energy levels in the body

C. To prove the relationship between emotions and color

D. Because vibrations make you healthy

Giả sử căn 3 là số hữu tỉ
căn 3 có dạng m/n với m/n tối giản
nên =>3n^2=m^2(1)
==>m có dạng 3p
==>n^2=3p==>n có dạng 3q
Vậy căn 3 =3p/3q=p/q ==> không phải tối giản ( trái với giả thiết trên)
==>căn 3 là vô tỉ

Một ô tô có khối lượng 1600kg đang chạy vói tốc độ 54 km/h thì người lái xe nhìn thấy một vật cản trước mặt cách khoảng 10m. Người đó tắt máy và hãm phanh khẩn cấp với lực hãm không đổi là 2 . 10 4   N . Xe dừng lại cách vật cản một khoảng bằng

A. 1,2 m.                     

B. 1,0 m.                   

C. 1,4 m.                   

D. l,5m.