A Rational Expression is an algebraic fraction which has polynomials in both the numerator and denominator.
Below are three examples of rational expressions:
The denominator of a fraction may not be 0. Any value for a variable that causes the denominator to equal 0 is called an excluded value.
For the first example, the excluded value is 2. For the second example, the excluded value is 2. And for the third example, there are two excluded values: 0, and 0.25.
Rational expressions can be simplified, as shown below: