Dividir $\frac{\left(\frac{\left(\frac{- 2}{7}- \left(1+\frac{- 5}{28}\right)+\frac{1}{4}\right)\cdot -3}{-1}\right)\cdot 9}{7}$

$\frac{186\frac{1681}{625}\cdot \frac{1}{2}}{\frac{1}{20}\cdot \frac{1}{20}\cdot \left(186-1\right)+\frac{1681}{625}\cdot \frac{1}{2}}$

$\frac{186\frac{1681}{625}\cdot \frac{1}{2}}{186-1+\frac{1681}{625}\cdot \frac{1}{2}}$

$\frac{6}{2\left(2+1\right)}$

$\frac{23^{\frac{1}{2}}}{33^{\frac{1}{2}}-6^{\frac{1}{2}}}$

$\frac{\left(8\right)\left(-1\right)}{\left(-11^2+4\right)^2}$

$\frac{2\sqrt{3}-\sqrt{2}}{\sqrt{18}}$

$\frac{2+\sqrt{3}}{2-\sqrt{3}}$