Answer:
D
Step-by-step explanation:
Distribute the negative 1 in the second group.
[tex]5k^4*-1=-5k^4 \\ 5k^3*-1=-5k^3 \\ -k*-1=k[/tex]
Now add by combining like terms.
[tex]3k^4-5k^4=-2k^4 \\ -2k^3-5k^3=-7k^3 \\ k+k=2k[/tex]
[tex]-2k^4-7k^3+2k[/tex]
