\[23 - 3 \cdot (b + 1) + 5 \cdot (6b - 7) - 7 \cdot (3b - 1) = 0\]
\[23 - 3b - 3 + 30b - 35 - 21b + 7 = 0\]
\[6b = 8\]
\[b = \frac{8}{6} = \frac{4}{3}\]
\[b = 1\frac{1}{3}.\ \]
\[Ответ:b = 1\frac{1}{3}.\]