Вычислите: 10 2/21+(7 1/2*2 2/3-12 1/4:7/9):6+3 1/8.

\[10\frac{2^{\backslash 8}}{21} + \left( 7\frac{1}{2} \cdot 2\frac{2}{3} - 12\frac{1}{4}\ :\frac{7}{9} \right)\ :6 + 3\frac{1^{\backslash 21}}{8} =\]

\[= 10\frac{16}{168} + 3\frac{21}{168} + \left( \frac{15}{2} \cdot \frac{8}{3} - \frac{49}{4} \cdot \frac{9}{7} \right) \cdot \frac{1}{6} =\]

\[= 13\frac{37}{168} + \left( 20 - \frac{63}{4} \right) \cdot \frac{1}{6} =\]

\[= 13\frac{37}{168} + \left( \frac{80}{4} - \frac{63}{4} \right) \cdot \frac{1}{6} =\]

\[= 13\frac{37}{168} + \frac{17}{4} \cdot \frac{1}{6} =\]

\[= 13\frac{37}{168} + \frac{17^{\backslash 7}}{24} =\]

\[= 13\frac{37}{168} + \frac{119}{168} = 13\ \frac{156}{168} =\]

\[= 13\frac{13}{14}.\]