При х = 4
х³ + 3x² + 5x – 1 = 4³ + 3 ⋅ 4² + 5 ⋅ 4 – 1 = 64 + 3 ⋅ 16 + 20 - 1 = 64 + 48 + 20 - 1 = 131
Ответ: 131
При х = -4
х³ + 3x² + 5x – 1 = (-4)³ + 3 ⋅ (-4)² + 5 ⋅ (-4) – 1 = -64 + 3 ⋅ 16 - 20 - 1 = -64 + 48 - 20 - 1 = -57
Ответ: -57