Answer:
Number 1 is a function. If you can draw a vertical line through the line graphed and it doesn't pass through it twice, it is considered a function.
Number 2 is B.
Number 3 is A. **I don't know this one for certain, but I graphed A and B for you.
I don't know number 4.
Number 5 is Beatz on Demand. This company charges $5.99 a month, while iTunez charges $8.99 a month.
Explanation:
Below is the graph for number 3.