\[\boxed{\text{356\ (356).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[1)\ 3x \cdot \left( 4x^{2} - x \right) = 12x^{3} - 3x^{2}.\]
\[2) - 5a^{2} \cdot \left( a^{2} - 6a - 3 \right) =\]
\[= - 5a^{4} + 30a^{3} + 15a^{2}\]
\[3)\ \left( 8b^{2} - 10b + 2 \right) \cdot 0,5b =\]
\[= 4b^{3} - 5b^{2} + b.\]
\[4)\ x^{3} \cdot \left( x^{5} - x^{2} + 7x - 1 \right) =\]
\[= x^{8} - x^{5} + 7x^{4} - x^{3}\text{.\ }\]
\[5) - 2c^{2}d^{4} \cdot \left( 4c^{2} - c^{3}d + 5d^{4} \right) =\]
\[= - 8c^{4}d^{4} + 2c^{5}d^{5} - 10c^{2}d^{8}.\]
\[= - 20m^{5}n^{9} + 32m^{3}n^{10} + 8m^{2}n^{14}\text{.\ }\]