Rationalizing the Denominator by Multiplying by a Conjugate
Rationalizing the denominator of a radical expression is a method used to eliminate radicals from a denominator. If the denominator is a binomial with a rational part and an irrational part, then you'll need to use the conjugate of the binomial.
Binomials of the form and are called conjugates. For example, and are conjugates.
The product of two conjugates results in a difference of two squares.
Multiply both the numerator and denominator by the conjugate of the denominator.
The denominator is now a difference of squares .
Use the power of a product property in the denominator.