Question

Write the simplest rationalization factor of the following surds :

$3\sqrt{72}$

• A. $\sqrt{2}$
• B. $\sqrt{3}$
• C. $\sqrt{5}$
• D. $\sqrt{7}$

Answer 1

The correct option is A $\sqrt{2}$

$3\sqrt{72}$
$=3\sqrt{2\times 2\times 2\times 3\times 3}$
$=3\times 3\times 2\sqrt{2}$
$=18\sqrt{2}$
The procedure of multiplying a surd by another surd to get a rational number is called RationalisationThe operands are called Rationalizing Factor (RF) of the other.Here, $\sqrt{2}$ is the Rationalisation Factor.