\[- 4a^{3}\left( 2a^{2} + a - 2 \right) + 8a^{5} =\]
\[= - 8a^{5} - 4a^{4} + 8a^{3} + 8a^{5} =\]
\[= - 4a^{4} + 8a³\]
\[при\ a = 2:\]
\[- 4 \cdot 16 + 8 \cdot 8 = - 64 + 64 = 0.\]