# Rational Expressions Calculator

**rational**” in math is not used in the sense of “

**sane**” or “

**sensible**.” It is instead used to imply a ratio, or fraction.

Rational expression is a fraction whose numerator and denominator is a polynomial function in variables.

**Example:**$\frac{x + 2}{x^{2}-3}$ is a rational expression.

We know that division by zero is not allowed since it makes the value of rational expression undefined. So it is always assumed that the denominator of a rational expression is never zero. This condition puts restrictions to the possible values of the variable.

**For example,**in a rational expression $\frac{2x + 3 }{x - 4}$, $x$ can never take the value of 4 since $x = 4$ will make the denominator zero and the expression undefined.