1) 2x - 7 + (6x + 1) = 18
2x - 7 + 6x + 1 = 18
8x - 6 = 18
8x = 24
x = 3
2) (4 - 8.2x) - (3.8x + 1) = 5
4 - 8.2x - 3.8x - 1 = 5
3 - 12x = 5
-12x = 2
x = -$$ \frac{1}{6} $$
Ответ: 1) x = 3, 2) x = -$$ \frac{1}{6} $$