4. Решите уравнение: a) 2x(3x - 2) - 3(x² - 4x) = 3x(x - 7) + 2 б) x/3 + x/12 = 15/4

a) 6x² - 4x - 3x² + 12x = 3x² - 21x + 2
3x² + 8x = 3x² - 21x + 2
8x = -21x + 2
29x = 2
x = 2/29
б) (4x + x) / 12 = 15/4
5x / 12 = 15/4
5x = (15 * 12) / 4
5x = 45
x = 9