Question

The simplest rationalizing factor of $\sqrt[4]{448}$ is

• A. $\sqrt[4]{49}$
• B. $\sqrt[4]{427}$
• C. $\sqrt[3]{39}$
• D. None of these

Answer 1

The correct option is B $\sqrt[4]{427}$

$\sqrt[4]{448}=\sqrt[4]{416\times 3}=2\sqrt[4]{43}$
So, we need three more 3's to make 3 come out of the root. Thus, the rationalizing factor is $\sqrt[4]{43^3}=\sqrt[4]{427}$.