\[\frac{b + 2}{2b - 8} + \frac{4 - b}{3b - 12} =\]
\[= \frac{b + 2^{\backslash 3}}{2 \cdot (b - 4)} + \frac{4 - b^{\backslash 2}}{3 \cdot (b - 4)} =\]
\[= \frac{3 \cdot (b + 2) + 2 \cdot (4 - b)}{6 \cdot (b - 4)} =\]
\[= \frac{3b + 6 + 8 - 2b}{6 \cdot (b - 4)} = \frac{b + 14}{6 \cdot (b - 4)}\]