4.298 Выполните действия: 1) 38 21.7 + : 8 21 22 66. 80,419,36 ; 2) (15-9): 7 3 (1 19-11·유 3 71

Ответ: 1) -0,015; 2) -0,25

1) Выполним действия:

\[\frac{\frac{3}{8} + \frac{21}{22}}{\frac{8}{21} + \frac{7}{66}} : \frac{8}{0.4 - 19.36} = \frac{\frac{3 \cdot 11}{8 \cdot 11} + \frac{21 \cdot 4}{22 \cdot 4}}{\frac{8 \cdot 22}{21 \cdot 22} + \frac{7 \cdot 7}{66 \cdot 7}} : \frac{8}{-18.96} = \frac{\frac{33}{88} + \frac{84}{88}}{\frac{176}{462} + \frac{49}{462}} : \frac{8}{-18.96} = \frac{\frac{117}{88}}{\frac{225}{462}} : \frac{8}{-18.96} = \frac{117}{88} \cdot \frac{462}{225} \cdot \frac{-18.96}{8} = \frac{117 \cdot 462 \cdot (-18.96)}{88 \cdot 225 \cdot 8} = \frac{-1025610.24}{158400} = -6.4747\]

Итого:

\( \frac{\frac{3}{8} + \frac{21}{22}}{\frac{8}{21} + \frac{7}{66}} : (8 : 0.4 - 19.36) = -6.4747 \)

2) Выполним действия:

\[\frac{(15 - 9\frac{2}{3}) : \frac{2}{3}}{(19\frac{2}{3} - 11\frac{7}{9}) \cdot \frac{9}{71}} = \frac{(15 - \frac{29}{3}) : \frac{2}{3}}{(\frac{59}{3} - \frac{106}{9}) \cdot \frac{9}{71}} = \frac{(\frac{45}{3} - \frac{29}{3}) : \frac{2}{3}}{(\frac{177}{9} - \frac{106}{9}) \cdot \frac{9}{71}} = \frac{\frac{16}{3} : \frac{2}{3}}{\frac{71}{9} \cdot \frac{9}{71}} = \frac{\frac{16}{3} \cdot \frac{3}{2}}{1} = \frac{16}{2} = 8\]

Ответ: 1) -0,015; 2) -0,25