Which is the completely factored form of 12x4 + 39x3 + 9x2? 3x2(x – 3)(4x – 1) 3x2(x + 3)(4x + 1) 3x(x + 3)(4x + 1) 3x(x – 3)(4x + 1)

First, take the GCF of all of the values

12x^4 + 39x^3 + 9x^2
3x^2( 4x^2 + 13x + 3)

Multiply the 'a' and 'c' values (4 and 3) to make factoring easier

4 X 3 = 12

Which two numbers multiply to get 12 and add to get 13? 1 and 12. How can 4 be go into those 2 values? 3 X 4 = 12

3x^2 ( 4x + 1)( x + 3)
3x^2 (x + 3)(4x + 1)

Hope this helps!