- в) $$1\frac{1}{6} + 3\frac{2}{3} = 7\frac{1}{6} - x$$
$$1\frac{1}{6} + 3\frac{4}{6} = 7\frac{1}{6} - x$$
$$4\frac{5}{6} = 7\frac{1}{6} - x$$
$$x = 7\frac{1}{6} - 4\frac{5}{6}$$
$$x = 6\frac{7}{6} - 4\frac{5}{6}$$
$$x = 2\frac{2}{6}$$
$$x = 2\frac{1}{3}$$
Ответ: $$x = 2\frac{1}{3}$$