Answer:
See below.
Step-by-step explanation:
[tex]-2x^4+16+2x^4+9-3x^5[/tex]
A helpful thing to do is to rearrange them in descending order:
[tex]=-3x^5-2x^4+2x^4+16+9[/tex]
We can see that the second and third term cancel. The fourth and fifth term are able to be added:
[tex]-3x^5+25[/tex]
Note: If you're confused on why [tex]-2x^4+2x^4[/tex] cancel, use the distributive property:
[tex]-2x^4+2x^4=x^4(-2+2)=x^4(0)=0[/tex]
