a) $$\frac{3}{9} - x = 1\frac{5}{9}$$
$$-x = 1\frac{5}{9} - \frac{3}{9}$$
$$-x = 1\frac{2}{9}$$
$$x = -1\frac{2}{9}$$
б) $$(y - 8\frac{12}{19}) + 1\frac{7}{19} = 10$$
$$y - 8\frac{12}{19} = 10 - 1\frac{7}{19}$$
$$y - 8\frac{12}{19} = 9\frac{12}{19}$$
$$y = 9\frac{12}{19} + 8\frac{12}{19}$$
$$y = 17\frac{24}{19}$$
$$y = 18\frac{5}{19}$$
Ответ: а) $$x = -1\frac{2}{9}$$, б) $$y = 18\frac{5}{19}$$