What is the rate of change of y with respect to x for this function?

Twelve less than a number is at most 20

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?

Which expression is a factor of 12x2 + 29x – 8? x – 8 2x – 1 3x + 8 4x + 1