TEXT: Intermediate Algebra by Miller, O’Neill & Hyde
Videos from Khan Academy.
A rational expression is a ratio of polynomials (p/q) with nonzero denominator (q≠0).
A rational expression can be simplified using the following principle:
Here is the first video:
The next 2 videos do more complicated situations and also find the domain. Rational expressions can be thought of as functions. The domain of a function is where it is defined (technically the set of inputs). To find the domain of a rational function, you find where the denominator is 0 and then exclude those points.
Multiplication of rational expressions relies on:
The next video gives a more complicated example:
To divide, we use the following principle to transform the quotient into a multiplication of rational expressions (and then use the multiplication property):
Here is a video presenting an example: