Answer:
-3x^{4}+2x^{3}+4x^{2}
Explanation:
Re-order terms so constants are on the left
-x^{2}\left( 3x^{2}-2x-4\right)
-x^{2}\left( 3x^{2}-2x-4\right)
2
Distribute
-\textcolor{#C58AF9}{x^{2}\left( 3x^{2}-2x-4\right) }
-\left( \textcolor{#C58AF9}{3x^{4}-2x^{3}-4x^{2}}\right)
3
Distribute
-\left( 3x^{4}-2x^{3}-4x^{2}\right)
-3x^{4}+2x^{3}+4x^{2}