Сократите дробь: (a-1)/(a-2√a+1).

\[\frac{a - 1}{a - 2\sqrt{a} + 1} = \frac{\left( \sqrt{a} - 1 \right)\left( \sqrt{a} + 1 \right)}{\left( \sqrt{a} - 1 \right)^{2}} = \frac{\sqrt{a} + 1}{\sqrt{a} - 1\ }\]