- 4*(2,3х - 3) - (5 - 2,6х) + 3(0,6х - 2) =
= - 4 * 2,3х - 4 *(-3) - 5 + 2,6х + 3 * 0,6х + 3 *(-2) =
= -9,2х +12 - 5 + 2,6х + 1,8х - 6 =
= (-9,2 + 2,6 +1,8 )* х + (12 - 5 - 6) =
= - 4,8х + 1
при х = 5/12
(- 4,8) * 5/12 + 1 = (- 24/5) * 5/12 + 1 = - 2 + 1 = - 1