4. Решите уравнения: a) 2x– 12(3 – x) = 1 + 3(x + 2); б) 16 + 5(– c – 2(c – 4)) = 12(3 – 2c) – 1.

a) Решим уравнение $$2x – 12(3 – x) = 1 + 3(x + 2)$$.

$$ 2x - 12(3 - x) = 1 + 3(x + 2) $$

$$ 2x - 36 + 12x = 1 + 3x + 6 $$

$$ 14x - 36 = 3x + 7 $$

$$ 14x - 3x = 7 + 36 $$

$$ 11x = 43 $$

$$ x = \frac{43}{11} $$

Ответ: $$x = \frac{43}{11}$$

б) Решим уравнение $$16 + 5(– c – 2(c – 4)) = 12(3 – 2c) – 1$$.

$$ 16 + 5(-c - 2(c - 4)) = 12(3 - 2c) - 1 $$

$$ 16 + 5(-c - 2c + 8) = 36 - 24c - 1 $$

$$ 16 + 5(-3c + 8) = 35 - 24c $$

$$ 16 - 15c + 40 = 35 - 24c $$

$$ 56 - 15c = 35 - 24c $$

$$ -15c + 24c = 35 - 56 $$

$$ 9c = -21 $$

$$ c = \frac{-21}{9} = -\frac{7}{3} $$

Ответ: $$c = -\frac{7}{3}$$