Решение:
а) $x - \frac{1}{2} = \frac{1}{2}$,
$x = \frac{1}{2} + \frac{1}{2}$,
$x = \frac{2}{2} = 1$;
б) $x - \frac{1}{3} = \frac{1}{4}$,
$x = \frac{1}{4} + \frac{1}{3}$,
$x = \frac{3 + 4}{12} = \frac{7}{12}$;
в) $x - \frac{1}{18} = \frac{1}{12}$,
$x = \frac{1}{12} + \frac{1}{18}$,
$x = \frac{3 + 2}{36} = \frac{5}{36}$;
г) $x - 1 = -\frac{1}{3}$,
$x = -\frac{1}{3} + 1$,
$x = \frac{2}{3}$;
д) $\frac{1}{7} + x = 11$,
$x = 11 - \frac{1}{7}$,
$x = 10\frac{6}{7}$;
е) $1\frac{1}{5} + x = 1$,
$x = 1 - 1\frac{1}{5}$,
$x = -\frac{1}{5}$;
ж) $x - 6\frac{1}{3} = -3\frac{2}{3}$,
$x = -3\frac{2}{3} + 6\frac{1}{3}$,
$x = 2\frac{2}{3}$;
з) $\frac{7}{9} + x = 2\frac{1}{2}$,
$x = 2\frac{1}{2} - \frac{7}{9}$,
$x = 2\frac{9}{18} - \frac{14}{18} = 1\frac{27}{18} - \frac{14}{18} = 1\frac{13}{18}$;
и) $x - 2\frac{1}{2} = -1\frac{3}{5}$,
$x = -1\frac{3}{5} + 2\frac{1}{2}$,
$x = -1\frac{6}{10} + 2\frac{5}{10} = 1\frac{15}{10} - 1\frac{6}{10} = \frac{9}{10}$.
Ответ:
а) $1;$
б) $\frac{7}{12};$
в) $\frac{5}{36};$
г) $\frac{2}{3};$
д) $10\frac{6}{7};$
е) $-\frac{1}{5};$
ж) $2\frac{2}{3};$
з) $1\frac{13}{18};$
и) $\frac{9}{10}.$