A rational expression is a fraction in which the numerator and denominator are polynomials and a complex rational expression is a fraction where the numerator and denominator are rational expressions.
For example, we can take the following rational expressions:
Both f(x) and g(x) are polynomial functions, we can use f(x) as the numerator of a complex rational expression and g(x) as the denominator to get:
Similarly, we can formulate 2 more complex rational expressions like this: