Classify the relations according to whether or not they are functions. (urgent)

The standard distance between studs in a house is 1.5 feet. if you have a set of blueprints for a house that mark every 1.5 feet with 2 in., by how many inches will a 13-foot wall be represented?

When only separate discreet points are graphed it is called?

Which expression gives you the distance between the points (5,1)and(9,-6)