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