This week in Precalculus 11, we started the Rational Expressions and Equations Unit. We first learned about equivalent rational expressions.

**rational expression: **a fraction with polynomials in the numerator & denominator

**non-permissable value:** variable values making the denominator 0

To determine the non-permissable values, we equate the denominator to 0 and solve the equation.

Example:

To simplify a rational expression, we first factor the numerator and denominator. We then identify the non-permissable values. Last, we cancel out identical pairs of numerators and denominators.

Example: