Algebra: Chapter 12, Lesson 3, page 547.
Linear Functions
A function `f` defined by an equation of the form `y=mx+b`, where `m` and `b` are real numbers, is a LINEAR function and can be written `f(x)=mx+b`.
If that is too confusing, forget the `f(x)` and just substitute `y` instead. Solve for the `f(x)` given the values specified in the domain (the `x` values) .