\[\boxed{\text{5.4}\text{3}\text{8.}}\]
\[\textbf{а)}\ 4\frac{7}{7} = 5\ \ \ \ \ \ \ \ \ \ \]
\[10\frac{24}{6} = 10 + \frac{24}{6} = 10 + 4 = 14\ \]
\[15\frac{77}{7} = 15 + \frac{77}{7} = 15 + 11 = 26\]
\[\textbf{б)}\ 4\frac{5}{4} = 5\frac{1}{4}\text{\ \ \ \ }\]
\[19\frac{17}{6} = 19 + \frac{17}{6} = 19 + 2\frac{5}{6} =\]
\[= 21\frac{5}{6}\ \]
\[7\frac{21}{5} = 7 + \frac{21}{5} = 7 + 4\frac{1}{5} = 11\frac{1}{5}\ \]