how to factor the gcf then factor it completely

Question

3x²+15x

Answer 1

3x² + 15x

 

Let's do a "prime factorization" of each term:

 

3x² = 3*x*x

15x = 3*5*x

 

The GCF is 3x, so let's factor that out.  You'll have an x left over from the 3x² term and a 5 left over from the 15x term:

 

3x² + 15x

 

3x*x + 3x*5

 

3x(x+5)

 

and we're done!