Question

Need help factoring this expression

Answer 1

3x+9

3 is a factor of both 3 and 9

3(x+3)

Answer 2

In order to factor the expression, you need to find one thing that's a factor of EACH term in the expression. So let's look at the terms.

-- factors of 3x :  1,  3,  x,  3x

-- factors of 9 :  1,  3,  9

The only things that are factors of both terms are 1 and 3.  We can ignore 1, because 1 is always a factor of anything.  That leaves us with 3 .  So we'll factor 3 out of the expression.

3x + 9  =  3 (x + 3)