factor polymials

Question

 

15x²+26x+7

Answer 1

Craig, we first multiply a x c, or 15 x 7 = 105.

 

Now, we need two factors of 105 that add up to b, or 26.

 

5 and 21 work. 5x + 21x = 26x.

 

15x² + 5x + 21x + 7

 

What do the first two terms have in common? 5x. 15x² + 5x = 5x(3x + 1).

 

What about the second two? 7, right? 7(3x + 1).

 

Now we have 5x(3x + 1) + 7(3x + 1). Since the parentheses are both the same, what's in front goes into their own set.

 

(5x + 7)(3x + 1)

 

Hope this helps!

Answer 2

15x^2+26x+7

15*7=3*5*7=5*(3*7)=5*21 and 5+21=26

(3x+1)(5x+7)