3. Решите уравнение
а) $$2 + 3x = -2x - 13$$
$$3x + 2x = -13 - 2$$
$$5x = -15$$
$$x = -3$$
Ответ: x = -3
б) $$2 - 3(2x + 1) = 5 - 4x$$
$$2 - 6x - 3 = 5 - 4x$$
$$-6x + 4x = 5 - 2 + 3$$
$$-2x = 6$$
$$x = -3$$
Ответ: x = -3
в) $$6(3x + 1) - 3x - 3x = 11x$$
$$18x + 6 - 3x - 3x = 11x$$
$$12x + 6 = 11x$$
$$12x - 11x = -6$$
$$x = -6$$
Ответ: x = -6