Question

$\text{The simplest form of}\sqrt{8}-3\sqrt{2}+\sqrt{98}$ is

• A. $6\sqrt{2}$
• B. $3\sqrt{2}$
• C. $2-3\sqrt{2}$

Answer 1

The correct option is A $6\sqrt{2}$

$\sqrt{8}-3\sqrt{2}+\sqrt{98}$
$=\sqrt{2\times 2\times 2}-3\sqrt{2}+\sqrt{2\times 7\times 7}$
$=\sqrt{2^2\times 2}-3\sqrt{2}+\sqrt{2\times 7^2}$
$=2\sqrt{2}-3\sqrt{2}+7\sqrt{2}$
$=9\sqrt{2}-3\sqrt{2}$
$=6\sqrt{2}$