( 5 1/30 - 2 3/5 - 2/15 + 6 ) - ( 7 - 6 11/12 + 1/4 ) Пожалуйста

Решите задачу:

$( \frac{51}{30} -2 \frac{3}{5}- \frac{2}{15}+6)-(7-6 \frac{11}{12}+ \frac{1}{4}) =( \frac{51}{30}- \frac{78}{30} - \frac{4}{30}+6)-7+ \frac{83}{12}- \frac{3}{12}$ $=( \frac{-31}{30}+6)-7+ \frac{80}{12} =( \frac{-31}{30}+ \frac{180}{30})- \frac{84}{12}+ \frac{80}{12} = \frac{149}{30}- \frac{4}{12}= \frac{149}{30} - \frac{1}{3}$ $= \frac{149}{30}- \frac{10}{30} = \frac{139}{30}=4 \frac{19}{30}$