\[\boxed{\text{5.457.}}\]
\[\textbf{а)}\ 9\frac{15}{5} = 9 + \frac{15}{5} = 9 + 3 = 12\ \]
\[11\frac{43}{43} = 12\ \]
\[\textbf{б)}\ 5\frac{10}{3} = 5 + \frac{10}{3} = 5 + 3\frac{1}{3} = 8\frac{1}{3}\ \]
\[15\frac{13}{8} = 15 + \frac{13}{8} = 15 + 1\frac{5}{8} =\]
\[= 16\frac{5}{8}\ \]
\[9\frac{29}{6} = 9 + \frac{29}{6} = 9 + 4\frac{5}{6} = 13\frac{5}{6}\text{\ \ }\]