-4(2,3x - 3) - (5 - 2,6x) + 3(0,6x - 2) = -9,2x + 12 - 5 + 2,6x + 1,8x - 6 = (-9,2x + 2,6x + 1,8x) + (12 - 5 - 6) = -4,8x + 1
Теперь подставим x = \frac{5}{12}:
-4,8 * (\frac{5}{12}) + 1 = -\frac{48}{10} * \frac{5}{12} + 1 = -\frac{4 * 12}{2 * 5} * \frac{5}{12} + 1 = -\frac{4}{2} + 1 = -2 + 1 = -1
Ответ: -1