已知函数y=a^x（a＞0且a≠1）在1，2上的最大值与最小值之和为20，记f（x）=$\frac{a^x}{a^x+2}$．

（1）求a的值；

（2）求f（x）+f（1﹣x）的值；

（3）求f（$\frac{1}{n}$）+f（$\frac{2}{n}$）+…+f（$\frac{n-1}{n}$）的值．

    Living and dealing with kids can be a difficult job these days, but living and dealing with parents can be even more complex.

    If I have learned anything in my 16 years, it is that communication is very important. With any relationship, you need to let other people know how you are feeling. If you are not able to communicate, you drift apart (疏远). When you are mad at your parents, or anyone else, not talking to them doesn't solve anything.

    Communication begins with the concerns of others. It means that you can't just come home from school, go up to your room and ignore everyone. To keep a good relationship, you must keep communication, even if it's just by writing a note.

    When dealing with parents, you always have to make them feel good about how they are doing as a parent. If you are trying to make them see something as you see it, tell them that you'll listen to what they have to say, but ask them politely to listen to you. Yelling or walking away only makes the situation worse.

    This is an example: one night, Sophie went to a street party with her friends. She knew she had to be home by midnight after the fireworks, but she didn't. She was late getting home. Her parents were mad at first, not giving Sophie a chance to explain why she was late. Later, they kept calm and listened to her. Communication is the key factor here. If Sophie's parents had not been willing to listen, Sophie would have been in a lot of trouble.