Answer:
1.This car has been fixed.
2.The purse was found.
3.The letter will be sent.
4.The new school is built.
5.The decision was made.
6.All the shoes were sold.
Explanation:
Passive forms are used when the speaker doesn't want to disclose extra information by giving a simple and straight forward answer.
As you can see,a lot of the unnecessary information has been removed and replaced by a simple clause, leaving only the much needed information only.