\[0,4b\left( 5b^{2} - 10 \right)\left( 2 + b^{2} \right) =\]
\[= 0,4b \cdot \left( 10b^{2} - 20 + 5b^{4} - 10b^{2} \right) =\]
\[+ = 4b^{3} - 8b + 2b^{5} - 4b^{3} = 2b^{5} - 8b\]