Question

81/88*(6-1 целая 13/15*1 целая 19/21)=

Answer 1

$\frac{81}{88}*(6-1\frac{13}{15}*1\frac{19}{21})=$

$\frac{81}{88}*(6-\frac{28}{15}*\frac{40}{21})=$

$=\frac{81}{88}*(6-\frac{32}{9})=$

$=\frac{81}{88}*(\frac{54-32}{9})=$

$=\frac{81*22}{88*9}=\frac{9}{4}=2\frac{1}{4}=2,25$