Cho hpt:$\left \{ {{(m-1)+y=m} \atop {x+(m-1)y=2}} \right.$
Tìm tất cả giá trị m nguyên để hpt có nghiệm duy nhất(x,y) và biểu thức
$\frac{2x-y}{x+y}$
Living in the country has both advantages and disadvantages. There are certainly many advantages to live in the country. First, you can enjoy peace and quietness. The air in the countryside is often fresher than in the city. Second, people tend to be friendlier. They live not very far from the others; they know each other very well. If someone needs help, they are ready to help anytime. Moreover, there is less traffic, so it is safer for young children. However, there are certain disadvantages to life outside the city. First, because there are fewer people, you are likely to have few friends. In addition, entertainment is difficult to find, particularly in the evening. Moreover, education seems to be less developed than it in the city. Therefore, the children are less accessed to the modern technology. On the whole, it is often the best for those who are retired or who have young children to live in the country. In contrast, young people who have a career are better provided in the city.
25. What is the topic of the writing?
26. How many advantages of living in the country mentioned?
27. Are there any disadvantages of living in the country?
28. Do you like to live in the city or in the countryside? Why?