# How do you simplify 4/sqrt(3) - 7/sqrt(27)?

$\frac{4}{\sqrt{3}} - \frac{7}{\sqrt{3 \cdot 9}} = \frac{4}{\sqrt{3}} - \frac{7}{\sqrt{3} \sqrt{9}} =$
$= \frac{4}{\sqrt{3}} - \frac{7}{3 \sqrt{3}} = \frac{12 - 7}{3 \sqrt{3}} = \frac{5}{3 \sqrt{3}} =$
$= \frac{5}{3 \sqrt{3}} \cdot \frac{\sqrt{3}}{\sqrt{3}} = \frac{5 \sqrt{3}}{9}$