Answer:
[tex]\boxed{6n^4- 10n^2 + 10n}[/tex]
Step-by-step explanation:
[tex](4n^4 - 3n^2 + n)+ (2n^4 -7n^2 + 9n)[/tex]
[tex]\sf Remove \ brackets.[/tex]
[tex]4n^4 - 3n^2 + n+2n^4 -7n^2 + 9n[/tex]
[tex]\sf Group \ like \ terms.[/tex]
[tex]4n^4 + 2n^4- 3n^2 -7n^2 + 9n+n[/tex]
[tex]\sf Combine \ like \ terms.[/tex]
[tex]6n^4- 10n^2 + 10n[/tex]
