[tex]\frac{\sqrt{50}-\sqrt{18}}{\sqrt{2}} = \frac{\sqrt{25\cdot2}-\sqrt{9\cdot2}}{\sqrt{2}} = \frac{\sqrt{25}\cdot\sqrt{2}-\sqrt{9}\cdot\sqrt{2}}{\sqrt{2}} = \frac{5\sqrt{2}-3\sqrt{2}}{\sqrt{2}} = \frac{2\sqrt{2}}{\sqrt{2}} =\boxed{ 2}[/tex]
[tex]\frac{2}{\sqrt{3}-1}-\frac{2}{\sqrt{3}+1} = \frac{2(\sqrt{3}+1)-2(\sqrt{3}-1)}{(\sqrt{3}-1)(\sqrt{3}+1)} = \frac{2\sqrt{3}+2-2\sqrt{3}+2}{\sqrt{3}^{2}-1^{2}} = \frac{4}{3-1} = \frac{4}{2} = \boxed{2}[/tex]
