Question

Which expression is equal to 2√54−4√24?

​ √6 ​

​−√6 ​

−2√6

−11√6

Answer 1

-2√6 , because 2√54 - 4√24= 2√9•6 - 4√4•6 = 6√6 - 8√6 = -2√6

Answer 2

Answer:

C. $-2\sqrt{ 6}$

Step-by-step explanation:

We have been given an expression. We are asked to simplify the given expression.

$2\sqrt{54}-4\sqrt{24}$

First of all, we will factor out perfect square under the radicals as shown  below:

$2\sqrt{9\cdot 6}-4\sqrt{4\cdot 6}$

$2\sqrt{3^2\cdot 6}-4\sqrt{2^2\cdot 6}$

Factor out perfect square:

$2\cdot 3\sqrt{6}-4\cdot 2\sqrt{ 6}$

$6\sqrt{6}-8\sqrt{ 6}$

Combine like terms:

$-2\sqrt{ 6}$

Therefore, option C is the correct choice.