# How do you simplify 2 sqrt 27 - 4 sqrt 3?

Apr 7, 2016

$= 2 \sqrt{3}$

#### Explanation:

$2 \sqrt{27} - 4 \sqrt{3}$

We first simplify $27$ by prime factorisation. (express a number as a product of its prime factors)

$27 = 3 \cdot 3 \cdot 3$

So, sqrt(27) = sqrt (3 * 3 * 3 ) = sqrt ( 3^2 * 3 ) = color(green)( 3sqrt3

$2 \sqrt{27} - 4 \sqrt{3} = 2 \cdot \textcolor{g r e e n}{3 \sqrt{3}} - 4 \sqrt{3}$

$= 6 \sqrt{3} - 4 \sqrt{3}$

$= 2 \sqrt{3}$