Преобразуем каждое выражение в одночлен стандартного вида:
-3x³y⁴x⁵ ⋅ 4y³ = (-3 ⋅ 4) ⋅ (x³ ⋅ x⁵) ⋅ (y⁴ ⋅ y³) = -12 ⋅ x³⁺⁵ ⋅ y⁴⁺³ = -12x⁸y⁷
(-4a⁶b)³ = (-4)³ ⋅ (a⁶)³ ⋅ b³ = -64 ⋅ a⁶⋅³ ⋅ b³ = -64a¹⁸b³
Ответ: 1) -12x⁸y⁷; 2) -64a¹⁸b³