16 1. -4m³n²· 2mn⁴

1) $$-4m^3n^2 \cdot 2mn^4 = -4 \cdot 2 \cdot m^3 \cdot m \cdot n^2 \cdot n^4 = -8 m^{3+1} n^{2+4} = -8 m^4 n^6$$

Ответ: $$-8 m^4 n^6$$