The polynomial 5x^2+15x has factors of 5x and which of the following ?

Question

The polynomial 5x^2+15x has factors of 5x and which of the following ?

Answer 1

5x² + 15x

 

5*x*x + 3*5*x

 

Both terms have a 5x in common, so factor a 5x out of each term,  If you take a 5x out of 5*x*x you're left with an x.  If you factor a 5x out of 3*5*x you're left with a 3:

 

5x*(x+3)