\[\boxed{\text{5.218.}}\]
\[\textbf{а)}\ \frac{x - 11}{15} = 16\]
\[x - 11 = 16 \cdot 15\]
\[x - 11 = 240\]
\[x = 240 + 11\]
\[x = 251.\ \]
\[Ответ:251.\ \]
\[\textbf{б)}\ \frac{54}{y + 7} = 6\]
\[y + 7 = 54\ :6\]
\[y + 7 = 9\]
\[y = 9 - 7\]
\[y = 2\text{.\ }\]
\[Ответ:2.\ \]
\[\textbf{в)}\ \frac{m + 6}{11} = 4\]
\[m + 6 = 11 \cdot 4\]
\[m + 6 = 44\]
\[m = 44 - 6\]
\[m = 38.\ \]
\[Ответ:38.\ \]
\[\textbf{г)}\ \frac{108}{20 - c} = 9\]
\[20 - c = 108\ :9\]
\[20 - c = 12\]
\[c = 20 - 12\]
\[c = 8.\ \]
\[Ответ:8.\ \ \ \]