## Precalculus (6th Edition) Blitzer

Complex rational expressions, or complex fractions have numerators and/or denominators containing rational expressions. For example, $\displaystyle \quad\frac{1+\frac{1}{x}}{\frac{x-1}{x+1}},\qquad \frac{\frac{a}{2}-\frac{3+a}{b}}{\frac{a+1}{b}}$ (These are first mentioned just before example 9)