57,4:4+1 1/6:4 2/3 -(2,7+ 5 1/20)*0,8...

$\frac{57,4 : 4+1 \frac{1}{6}: 4 \frac{2}{3}-(2,7+5 \frac{1}{20}) *0,8 }{2 \frac{1}{15}-(1 \frac{2}{3} + \frac{1}{5}) }$ =

$\frac{14,35+ \frac{7}{6}: \frac{14}{3}-(2,7+ \frac{101}{20} )*0,8 }{ \frac{31}{15}- \frac{5}{3}+ \frac{1}{5} }$ =

$\frac{14,35+ \frac{1}{4}-(2,7+5,05)*0,8 }{ \frac{31}{15}- \frac{28}{15} }$ =

$\frac{14,35+0,25-6,2}{ \frac{1}{5} }$ = $\frac{8,4}{0,2}$ =42