9. Решите уравнение: 1) $$8\frac{7}{9} - x = 3\frac{5}{6}$$; 2) $$(x - \frac{5}{6}) + \frac{11}{18} = \frac{19}{24}$$.

Решение: 1) $$8\frac{7}{9} - x = 3\frac{5}{6}$$ x = $$8\frac{7}{9} - 3\frac{5}{6}$$ x = $$\frac{79}{9} - \frac{23}{6}$$ x = $$\frac{79 \cdot 2 - 23 \cdot 3}{18}$$ x = $$\frac{158 - 69}{18}$$ x = $$\frac{89}{18}$$ x = $$4\frac{17}{18}$$ 2) $$(x - \frac{5}{6}) + \frac{11}{18} = \frac{19}{24}$$ x - $$\frac{5}{6}$$ = $$\frac{19}{24} - \frac{11}{18}$$ x - $$\frac{5}{6}$$ = $$\frac{19 \cdot 3 - 11 \cdot 4}{72}$$ x - $$\frac{5}{6}$$ = $$\frac{57 - 44}{72}$$ x - $$\frac{5}{6}$$ = $$\frac{13}{72}$$ x = $$\frac{13}{72} + \frac{5}{6}$$ x = $$\frac{13 + 5 \cdot 12}{72}$$ x = $$\frac{13 + 60}{72}$$ x = $$\frac{73}{72}$$ x = $$1\frac{1}{72}$$ Ответы: 1) $$x = 4\frac{17}{18}$$; 2) $$x = 1\frac{1}{72}$$