2) 0.2v^3 + 0.4v^2 - 0.8v^3 - 0.3v^2 + 0.9v^3 + 0.8v - 1 при v = 2.

Приводим подобные члены: (0.2v^3 - 0.8v^3 + 0.9v^3) + (0.4v^2 - 0.3v^2) + 0.8v - 1 = 0.3v^3 + 0.1v^2 + 0.8v - 1. Подставляем v = 2: 0.3(2)^3 + 0.1(2)^2 + 0.8(2) - 1 = 2.4 + 0.4 + 1.6 - 1 = 3.4.