what is

$$\\\frac{\sqrt{10}}{10}+\frac{1}{\sqrt{10}}\\\\ =\frac{\sqrt{10}}{10}+\frac{1*\sqrt{10}}{\sqrt{10}*\sqrt{10}}\\\\ =\frac{\sqrt{10}}{10}+\frac{\sqrt{10}}{10}\\\\ =\frac{2\sqrt{10}}{10}\\\\ =\frac{\sqrt{10}}{5}\\\\$$