How to solve lineure equations

In what form is the following linear equation written y=9x+2

For which of the following counts would a binomial probability model not be reasonable? a)the number of people in a classroom born in januaryb) the number of people in a classroom with red hair c) the number of people admitted to a hospital in a day with a particular disease d) the number of heart beats in a one-minute perio.

Consider the function f(x)=-5x+3 what is f(-2)