# How do you simplify -2sqrt27-3sqrt27+3sqrt18?

$- 2 \sqrt{27} - 3 \sqrt{27} + 3 \sqrt{18}$
$= - 2 \sqrt{{3}^{2} \cdot 3} - 3 \sqrt{{3}^{2} \cdot 3} + 3 \sqrt{{3}^{2} \cdot 2}$
$= - 2 \left(3 \sqrt{3}\right) - 3 \left(3 \sqrt{3}\right) + 3 \left(3 \sqrt{2}\right)$
$= - 15 \sqrt{3} + 9 \sqrt{2}$