Please help me for 5 points​

Which is an equation for the nth terms of the sequence 12,15,18,21

Afactory adds 3 red drops and 2 blue drops of coloring to white paint to make each pint of purple paint. the factory will make 50 gallons of the purple paint.how many drops of red and blue coloring will the factory need in the 50 gallon batch of purple paint.

Thelime contains the point(-3,0) and parallel x-3y=3( show all work)