a) $$-1,4a^2b \cdot 4a^4b^8 = -1,4 \cdot 4 \cdot a^{2+4} \cdot b^{1+8} = -5,6a^6b^9$$
б) $$(4xyz^2)^3 = 4^3x^3y^3(z^2)^3 = 64x^3y^3z^6$$
в) $$(-2x^3)^4 \cdot 10x^3 = (-2)^4 (x^3)^4 \cdot 10x^3 = 16x^{12} \cdot 10x^3 = 16 \cdot 10 \cdot x^{12+3} = 160x^{15}$$
Ответ: а) $$-5,6a^6b^9$$, б) $$64x^3y^3z^6$$, в) $$160x^{15}$$