30 целых 5/6 - (7 целых 1/3 +2 целых 1/4) : 1/4

Решите задачу:

$30 \frac{5}{6} - (7 \frac{1}{3} +2 \frac{1}{4} ) : \frac{1}{4} =30 \frac{5}{6} - (7 \frac{4}{12} +2 \frac{3}{12} ) : \frac{1}{4} =30 \frac{5}{6} - 9 \frac{7}{12} : \frac{1}{4} =$ $30 \frac{5}{6} - \frac{115}{12} *\frac{4}{1} =30 \frac{5}{6} - \frac{115}{3} =30 \frac{5}{6} - 38\frac{1}{3} =30 \frac{5}{6} - 38\frac{2}{6} =-8 \frac{3}{6} =-8 \frac{1}{2}$