[tex]\it\ \sqrt5^5:(-\sqrt{5^3})=-\sqrt5^5:\sqrt5^3=-\sqrt5^{5-3}=-\sqrt5^2=-5\\ \\ 2\cdot\sqrt{0,(3)}\cdot\Big(\dfrac{1}{\sqrt3}\Big)^{-3}=2\sqrt{\dfrac{3}{9}}\cdot(\sqrt3)^3=2\dfrac{\sqrt3}{3}\cdot3\sqrt3=2\cdot3=6\\ \\ a=-5+6=1\\ \\ (a-2)^{2019}=(1-2)^{2019}=(-1)^{2019}=-1[/tex]