Решите уравнения: a) (x - 12/63) - 38/63 = 4/63; б) 18/19 - (8/19 + (14/19 - x)) = 2/19.

a) $$ (x - \frac{12}{63}) - \frac{38}{63} = \frac{4}{63} $$.

$$ x - \frac{12}{63} - \frac{38}{63} = \frac{4}{63} $$.

$$ x = \frac{4}{63} + \frac{12}{63} + \frac{38}{63} $$.

$$ x = \frac{4+12+38}{63} $$.

$$ x = \frac{54}{63} = \frac{6}{7} $$.

б) $$ \frac{18}{19} - (\frac{8}{19} + (\frac{14}{19} - x)) = \frac{2}{19} $$.

$$ \frac{18}{19} - \frac{8}{19} - \frac{14}{19} + x = \frac{2}{19} $$.

$$ \frac{18 - 8 - 14}{19} + x = \frac{2}{19} $$.

$$ \frac{-4}{19} + x = \frac{2}{19} $$.

$$ x = \frac{2}{19} + \frac{4}{19} $$.

$$ x = \frac{2+4}{19} = \frac{6}{19} $$.

Ответ: а) 6/7; б) 6/19.