\[16x^{2} + 2(b - 4)x + (2 - 3b) =\]
\[= 0;\ \ \ \ x = 4\]
\[16 \cdot 16 + (2b - 8) \cdot 4 + 2 - 3b =\]
\[= 0\]
\[256 + 8b - 32 + 2 - 3b = 0\]
\[5b = - 226\ \]
\[b = - \frac{226}{5}\]
\[b = - 45,5.\]