What's the difference?

What is the range of the relation in the table below? x y –2 0 –1 2 0 4 1 2 2 0

If u good at math hit me up on insta or sum @basic_jaiden or @ and

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour. what is the cyclist average rate for the round trip in miles per hour ?