Given radical expression:
.
We need to find the fraction by which fraction will produce an equivalent fraction with a rational denominator.
In the given expression, we have 
Which is an irrational number in denominator.
In order to get rid irrational number from denominator and get a rational number in denominator, we need to multiply given expression by conjugate of the denominator.
The conjugate of
is
.
<h3>Therefore, we need to multiply

by

fraction that will produce an equivalent fraction with a rational denominator.</h3>