\[\left( 10 - 12y^{2} \right) - \left( y^{3} - y^{2} + 6 \right) =\]
\[= 10 - 12y^{2} - y^{3} + y^{2} - 6 =\]
\[= - y^{3} - 11y^{2} + 4\]