\[\boxed{\text{5.\ 97}}\]
\[\textbf{а)}\ 7x - 21 = 6x + 3\]
\[7x - 6x = 3 + 21\]
\[x = 24.\ \]
\[\textbf{б)} - 10n + 7 = - 11n - 3\]
\[- 10n + 11n = - 3 - 7\]
\[n = - 10.\]
\[\textbf{в)}\ 5c + 13 = 6c + 23\]
\[5c - 6c = 23 - 13\]
\[- c = 10\]
\[c = - 10.\]
\[\textbf{г)} - 24c - 9 = 23c - 9\]
\[- 24c - 23c = - 9 + 9\]
\[- 45c = 0\]
\[c = 0.\]
\[\textbf{д)}\ 8 + 27a = 10 + 26a\]
\[27a - 26a = 10 - 8\]
\[a = 2.\]
\[\textbf{е)}\ 13 - 7x = 14 - 8x\]
\[- 7x + 8x = 14 - 13\]
\[x = 1.\]
\[\textbf{ж)}\ 9n + 6 = - 4 + 10n\]
\[9n - 10n = - 4 - 6\]
\[- n = - 10\]
\[n = 10.\]
\[\textbf{з)}\ 2 - 5x = 4 - 6x\]
\[- 5x + 6x = 4 - 2\]
\[x = 2.\]