1) Найдите значение выражения: $$5/9+4/9 \cdot 3 \frac{1}{6} \cdot (\frac{4}{19}+1 \frac{5}{38}-\frac{75}{76})$$
Решение:
$$5/9+4/9 \cdot 3 \frac{1}{6} \cdot (\frac{4}{19}+1 \frac{5}{38}-\frac{75}{76})=$$
$$=5/9+4/9 \cdot \frac{19}{6} \cdot (\frac{4}{19}+\frac{43}{38}-\frac{75}{76})=$$
$$=5/9+4/9 \cdot \frac{19}{6} \cdot (\frac{4 \cdot 4}{19 \cdot 4}+\frac{43 \cdot 2}{38 \cdot 2}-\frac{75}{76})=$$
$$=5/9+4/9 \cdot \frac{19}{6} \cdot (\frac{16}{76}+\frac{86}{76}-\frac{75}{76})=$$
$$=5/9+4/9 \cdot \frac{19}{6} \cdot (\frac{16+86-75}{76})=$$
$$=5/9+4/9 \cdot \frac{19}{6} \cdot \frac{27}{76}=$$
$$=5/9+\frac{4 \cdot 19 \cdot 27}{9 \cdot 6 \cdot 76}=$$
$$=5/9+\frac{4 \cdot 19 \cdot 9 \cdot 3}{9 \cdot 6 \cdot 19 \cdot 4}=$$
$$=5/9+\frac{3}{6}=$$
$$=5/9+\frac{1}{2}=$$
$$=\frac{5 \cdot 2}{9 \cdot 2}+\frac{1 \cdot 9}{2 \cdot 9}=$$
$$=\frac{10}{18}+\frac{9}{18}=$$
$$=\frac{10+9}{18}=$$
$$=\frac{19}{18}=1 \frac{1}{18}$$
Ответ: $$1 \frac{1}{18}$$