Решаем по порядку от F(1) к F(8)F(1) = 4F(2) = 5F(3) = 4*F(3-1) - 3*F(3-2) = 4*F(2) - 3*F(1) = 4*5 - 3*4 = 20-12 = 8F(4) = 4*F(4-1) - 3*F(4-2) = 4*F(3) - 3*F(2) = 4*8 - 3*5 = 32-15 = 17F(5) = 4*F(5-1) - 3*F(5-2) = 4*F(4) - 3*F(3) = 4*17 - 3*8 = 68-24 = 44F(6) = 4*F(6-1) - 3*F(6-2) = 4*F(5) - 3*F(4) = 4*44 - 3*17 = 176-51 = 125F(7) = 4*F(7-1) - 3*F(7-2) = 4*F(6) - 3*F(5) = 4*125 - 3*44 = 500-132 = 368F(8) = 4*F(8-1) - 3*F(8-2) = 4*F(7) - 3*F(6) = 4*368 - 3*125 = 1472-132 = 1097Ответ: 1097