{3 \frac{1}{4}-\frac{4}{5} { \of } \frac{5}{6}}/{4 \frac{1}{3} \\div\frac{1}{5}-(\frac{3}{10}+21 \frac{1}{5})}-(1 \frac{2}{3} of 1 \frac{1}{2}) is equal to