Решите уравнения: a) 37/76 - (69/76 - x) = 15/76; б) 5/18 + 15/18 - (x - 7/18) = 11/18.

а) $$ \frac{37}{76} - (\frac{69}{76} - x) = \frac{15}{76} $$.

$$ \frac{37}{76} - \frac{69}{76} + x = \frac{15}{76} $$.

$$ x = \frac{15}{76} - \frac{37}{76} + \frac{69}{76} $$.

$$ x = \frac{15 - 37 + 69}{76} $$.

$$ x = \frac{47}{76} $$.

б) $$ \frac{5}{18} + \frac{15}{18} - (x - \frac{7}{18}) = \frac{11}{18} $$.

$$ \frac{5}{18} + \frac{15}{18} - x + \frac{7}{18} = \frac{11}{18} $$.

$$ \frac{5+15+7}{18} - x = \frac{11}{18} $$.

$$ \frac{27}{18} - x = \frac{11}{18} $$.

$$ x = \frac{27}{18} - \frac{11}{18} $$.

$$ x = \frac{27-11}{18} $$.

$$ x = \frac{16}{18} = \frac{8}{9} $$.

Ответ: а) 47/76; б) 8/9.