\[(b - 1)^{2} \cdot \left( \frac{1}{b^{2} - 2b + 1} + \frac{1}{b^{2} - 1} \right) + \frac{2}{b + 1}\]
\[\frac{1}{b^{2} - 2b + 1} + \frac{1}{b^{2} - 1} =\]
\[= \frac{1^{\backslash b + 1}}{(b - 1)^{2}} + \frac{1^{\backslash b - 1}}{(b - 1)(b + 1)} =\]
\[= \frac{b + 1 + b - 1}{(b - 1)^{2}(b + 1)} =\]
\[= \frac{2b}{(b - 1)^{2}(b + 1)}\]
\[(b - 1)^{2} \cdot \frac{2b}{(b - 1)^{2}(b + 1)} =\]
\[= \frac{2b}{b + 1}\ \]
\[\frac{2b}{b + 1} + \frac{2}{b + 1} = \frac{2b + 2}{b + 1} =\]
\[= \frac{2(b + 1)}{b + 1} = 2.\]
\[Выражение\ при\ b
eq \pm 1\ не\ \]
\[зависит\ от\ \text{b.}\]
\[Что\ и\ требовалось\ доказать.\]