Answer:
[tex]\large\boxed{4n^5+3.5n^5+(-2.1n^5)=5.4n^5}[/tex]
Step-by-step explanation:
[tex]4n^5+3.5n^5+(-2.1n^5)=4n^5+3.5n^5-2.1n^5\qquad\text{combine like terms}\\\\=(4+3.5-2.1)n^5=5.4n^5[/tex]
