Can some one help me please with this questions

Sam is a waiter at a local restaurant where he earns wages of $5 per hour sam figures that he also eams about $3 in tips for each person he serves sam works 6 hours on a particular day. if n represents the number of people sam serves that day, which of the following functions could sam use to figure ehis total earings for the do o a. en) = 30 o b. en) = 5n+ 18

Which of the following graphs could represent a cubic function?

The price of a car has been reduced from $19,000 to $11,590. what is the percentage decrease of the price of the car?