-9y^2+x² разложите на множители ​

Помогите перевести тект

полный синтаксический разбор предложения "Часы Кулибина раскрывали удивительное дарование мастера, они являли собой чудо русской техники."

Постройте предложения относительно примеру.

Какое это правило не помню :3

Example:

It is simple to solve this problem. --- This problem is simple to solve.

It is difficult to speak to such people. --- Such people are difficult to speak to.

Упрожнение:

1. It is expensive to buy a mink coat.

2. It is impossible to get a good dinner in our canteen.

3. It was difficult to start an engine in such cold weather.

4. It is dangerous to stand on this ladder.

5. It is rather difficult to deal with stubborn people.

6. It is dangerous to drive a car in big cities.

7. It is interesting to meet new people.

8. It is simple to communicate with people due to Internet.

9. It was unpleasant to watch their quarrel.

10. It is always funny to lister to him.