Question

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)

Answer 1

The second option, 3x^2(x+3)(4x+1)

Explanation:

Factor out the common term, which is 3x^2

This then becomes 3x^2(4x^2+13x+3)

Factor the inside term and it becomes

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