Question

gcf of 5x^4+15x

Answer 1

http://www.dummies.com/how-to/content/how-to-find-a-greatest-common-factor-in-a-polynomi.html should help you greatly

Answer 2

Now to easily simplify this, what we would do is put this in a easy format:
\[5x^{4}+15x\]

Answer 3

Now we have to think 'What is the GCF of 15 and 5?' Well here is an easy way, list the factors. What is the factors of 15 and 5?