Answer
$3 \sqrt 6$
Work Step by Step
$\sqrt 6 + \sqrt 24$
$\sqrt 24$ can be written as 4 x 6 because they are the factors of 24
$\sqrt 6 + \sqrt (4 \times 6)$
We see that it has the common factor of $\sqrt 6$ so we factor it out.
$\sqrt 6 ( 1 + \sqrt 4 )$
*** Square root of 4 is 2 because 2 x 2 =4
$\sqrt 6 ( 1 + 2)$
$\sqrt 6 (3)$
$3 \sqrt 6$