The surgeon's job is traditionally most common for men. Surgeons have to perform operations on patients. They also have to make important decisions about patients' health and safety. Besides medical knowledge, surgeons need both physical and mental strength to perform long and tiring operations. In addition, surgeons need to have excellent eyesight and skilful hands. A surgeon works with a team, so he / she needs good teamwork and communication skills. Although it is traditionally seen as a male job, the number of women surgeons is increasing now. Women as mentally strong as men, and they can perform long operations. In summary, women can make great surgeons, and everybody will benefit from having both male and female surgeons.

The surgeon's job is traditionally most common for men. Surgeons have to perform operations on patients. They also have to make important decisions about patients' health and safety. Besides medical knowledge, surgeons need both physical and mental strength to perform long and tiring operations. In addition, surgeons need to have excellent eyesight and skilful hands. A surgeon works with a team, so he / she needs good teamwork and communication skills. Although it is traditionally seen as a male job, the number of women surgeons is increasing now. Women as mentally strong as men, and they can perform long operations. In summary, women can make great surgeons, and everybody will benefit from having both male and female surgeons.

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Florence Nightingale is most famous for being the founder of modern nursing.

She was born in 1820 in Florence, Italy. She grew up in England with her parents and older sister. In 1844, she studied nursing in Germany and later went to London to work in a hospital. In 1854, Florence went to the military hospital in Scutari, Turkey, with 38 other women. They cleaned the hospital and improved conditions for the wounded soldiers. The death rate dropped from sixty percent to two percent within six months. In 1855, Queen Victoria gave Florence an award and a piece of jewelry. Florence wrote Notes on Nursing in 1859 and in 1860, she opened St. Thomas' Hospital where she started the Nightingale Training School for Nurses. In 1908, she was given the merit of honor by King Edward VII. She died two years later in London. Florence Nightingale will be remembered for being the founder of modern nursing.

Đầu kiện: \(x+y\ne0\Leftrightarrow x\ne-y\)

Ta có:

\(3x^3-y^3=\dfrac{1}{x+y}\\ \Leftrightarrow\left(3x^3-y^3\right)\left(x+y\right)=1\\ \Leftrightarrow\left(3x^3-y^3\right)\left(x+y\right)=\left(x^2+y^2\right)^2\)(*)

Xét \(y=0\Rightarrow x=\pm1\) thay vào phương trình (*) ta thấy không thõa mãn.

Với \(y\ne0\) chia hai vế phương trình (*) cho \(y^4\) ta có:

\(\dfrac{\left(3x^3-y^3\right)\left(x+y\right)}{y^4}=\dfrac{\left(x^2+y^2\right)^2}{y^4}\\ \Leftrightarrow\left(\dfrac{3x^3}{y^3}-1\right)\left(\dfrac{x}{y}+1\right)=\left(\dfrac{x^2}{y^2}+1\right)^2\)

Đặt \(t=\dfrac{x}{y}\) thay vào phương trình trên ta có:

\(\left(3t^3-1\right)\left(t+1\right)=\left(t^2+1\right)^2\)

\(\Leftrightarrow3t^4-t+3t^3-1=t^4+2t^2+1\\ \Leftrightarrow2t^4+3t^3-2t^2-t-2=0\\ \)

\(\Leftrightarrow2t^3\left(t+2\right)-t^2\left(t+2\right)-\left(t+2\right)=0\\ \Leftrightarrow\left(t+2\right)\left(2t^3-t^2-1\right)=0\\ \Leftrightarrow\left(t+2\right)\left(t^3-1+t^3-t^2=0\right)\\ \Leftrightarrow\left(t+2\right)\left(t-1\right)\left(2t^2+t+1\right)=0\\ \)

\(\Rightarrow\left[{}\begin{matrix}t+2=0\\t-1=0\\2t^2+t+1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}t=-2\\t=1\\\Delta< 0,vô.nghiệm\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-2y\\x=y\end{matrix}\right.\)

Thay x vào phương trình \(x^2+y^2=1\) tìm y => x.

So với đầu kiện bài toán kết luận nghiệm

From : ...

To : ...

Subject : The camera

Hi,

I'm ........ Are you the company called : ....... that product camera? I have a litte issue about your camera : Last week, I went to the store and bought a new camera which is made by your company. I like it very much. But this morning, when I'm going to take a picture of a flower, I realize that it isn't working any more. I checked it again and it's still not working. I didn't do anything like drop it to the ground since I bought it. I think there's some problem inside it. I'm really worry about the camera. What do you think the problem is? Can you come to my house and check the camera? I'm free tomorrow. If you can, please come by. Here's my address : ...........

Thank you!

cô mà không giải đc sao tụi nào giải đc đồ đi*ên

phonissong

My sister and I attended the F5 tour at the National Stadium last night. I could sum up the concert in one word, INCREDIBLE. We found our way up to our seats after having a light meal and stood in a queue at the gate of the stadium for 45 minutes. When the curtain was raised to reveal the F5 band, the entire stadium went absolutely crazy. I was thrilled by every of their performances. There was so much emotion in many of their songs, and the way they performed was so terrific. This was such a wonderful experience, a night that I'll never forget. I'm so grateful to have been able to have that experience.

Last week , i went to a charity concert with my sister , it called : FPC ( for poor children ) .  Because the fare will be for poor children , I and my sister invited more friends to join us . It was held at Hoang Mai Stadium in Hanoi , at 6p.m. It is 40 minutes form my house to Hanoi if I go by bus , so I and my sister need to be in at 5:30 p.m to catch the bus . At the concert, there were many spectators involved. Featuring famous singers, the concert was more lively than ever. Both the songs and the lively dances are exciting . Although I don't like music, when I came to a charity concert, I felt very happy that I was able to help poor children get food and clothing.

Nếu bỏ người thứ nhất đi thì số người còn lại là k người nhưng số người thực tế bằng tuổi nhau chỉ là k-1 vì với n = k thì có  k người bằng tuổi nhau , khi bỏ đi người thứ nhất thì chỉ còn lại k-1 người bằng tuổi nhau và một người nữa , lập luận còn lại k người bằng tuổi nhau là sai