S5 = 5/2 (2 a1 + (5 - 1) d) = 5/2 (2 0.1 + (5 - 1) 8) = 5/2 (0.2 + 4 8) = 5/2 (0.2 + 32) = 5/2 32.2 = 80.5.
Ответ: S5 = 80.5.
S5 = 5/2 (2 a1 + (5 - 1) d) = 5/2 (2 0.1 + (5 - 1) 8) = 5/2 (0.2 + 4 8) = 5/2 (0.2 + 32) = 5/2 32.2 = 80.5.
Ответ: S5 = 80.5.