Answer: k=0,-5
Explanation:
Your GCF is 5k, as you're able to take it out of both terms.
Once you've taken out a 5k, this will leave you with an equation that looks like this;5k(k+5)=0.
Set your 5k equal to 0 and divide to get k=0
Set your k+5 equal to 0 and subtract on both sides to get k=-5
Hope this helps you, dawg.