Which explains whether or not the function represents a direct variation?
This function represents a direct variation because it
passes through the origin and has a constant rate of
change of $5 per hour.
This function represents a direct variation because it
has a positive, constant rate of change of $10 per
hour.
This function does not represent a direct variation
because it does not represent the cost for 1 hour.
This function does not represent a direct variation
because the function rule for the cost is to add $10,
not multiply by a constant.