Suppose the population P of a certain species of fish depends on the number x (in hundreds) of a smaller fish that serves as its food supply, so that

                                           P(x) = 2x² + 1.

Suppose, also, that the number of the smaller species of fish depends on the amount a (in appropriate units) of its food supply, a kind of plankton. Specifically,

                                           x = ƒ(a) = 3a + 2.

A biologist wants to find the relationship between the population P of the large fish and the amount a of plankton available, that is, P [ ƒ(a)]. What is the relationship?