You can put this solution on YOUR website!
When you look at the polynomial, what is a factor that every term has in common with one another?
The answer is 3x because, 3x(7x^2-2x+5)
21x^3 is divided by 3x to get 7x^2
-6x^2 is divided by 3x to get -2x
15x is divided by 3x to get 5
So the GFC(Greatest Common Factor) is 3x
To check your work multiply 3x by the factored set of terms
3x(7x^2-2x+5) to get 21x^3-6x^2+15x
Hope this helps...