Решим уравнение:
$$ (x + 4 \frac{2}{7}) - 3 \frac{6}{7} = 6 $$
$$ x + 4 \frac{2}{7} = 6 + 3 \frac{6}{7} $$
$$ x + 4 \frac{2}{7} = 9 \frac{6}{7} $$
$$ x = 9 \frac{6}{7} - 4 \frac{2}{7} $$
$$ x = 5 \frac{4}{7} $$
Ответ: $$x = 5 \frac{4}{7} $$