\[\frac{2b^{2} - 3b + 4}{(b - 1)^{2}} - \frac{b - 2^{\backslash b - 1}}{b - 1} =\]
\[= \frac{2b^{2} - 3b + 4 - (b - 2)(b - 1)}{(b - 1)^{2}} =\]
\[= \frac{2b^{2} - 3b + 4 - b^{2} + 3b - 2}{(b - 1)^{2}} =\]
\[= \frac{b^{2} + 2}{(b - 1)^{2}}\]