Ивычислите: -4(2,3x--2,6x)+3(0,6x-2)

- 4 * (2,3х - 3) - (5 - 2,6х) + 3 * (0,6х - 2) =
= - 9,2х + 12 - 5 + 2,6х + 1,8х - 6 =
= - 4,8х +1 = 1 - 4,8х

При х = 5/12
1- 4,8х = 1 - 4,8 * 5/12 = 1 - 4 8/10 * 5/12 = 1 - 48/10 * 5/12 = 1 - 48*5/10*12 =
= 1 - 240/120 = 1 - 2 = -1