г) |-1,8|::e)-30|-|-0,54

б) $$ |-1,8| : \frac{3}{25} = 1,8 : \frac{3}{25} = 1,8 \cdot \frac{25}{3} = \frac{18}{10} \cdot \frac{25}{3} = \frac{6}{2} \cdot 5 = 3 \cdot 5 = 15 $$.

е) $$ |-3\frac{8}{9}| - |-0,54| = 3\frac{8}{9} - 0,54 = 3\frac{8}{9} - \frac{54}{100} = 3\frac{8}{9} - \frac{27}{50} = \frac{35}{9} - \frac{27}{50} = \frac{35 \cdot 50}{9 \cdot 50} - \frac{27 \cdot 9}{50 \cdot 9} = \frac{1750}{450} - \frac{243}{450} = \frac{1507}{450} = 3\frac{157}{450} $$.

Ответ: б) 15; е) $$3\frac{157}{450}$$