Answer:
D. -4x(x - 2)(x+3)
Step-by-step explanation:
We are given the following trinomial:
[tex]-4x^3 - 4x^2 + 24x[/tex]
-4x is the common term, so:
[tex]-4x(\frac{-4x^3}{-4x} - \frac{4x^2}{-4x^3} + \frac{24x}{-4x}) = -4x(x^2+x-6)[/tex]
The second degree polynomial can also be factored, finding it's roots.
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
[tex]ax^{2} + bx + c, a\neq0[/tex].
This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:
[tex]x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}[/tex]
[tex]x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}[/tex]
[tex]\Delta = b^{2} - 4ac[/tex]
x² + x - 6
Quadratic equation with [tex]a = 1, b = 1, c = -6[/tex]
So
[tex]\Delta = 1^{2} - 4(1)(-6) = 25[/tex]
[tex]x_{1} = \frac{-1 + \sqrt{25}}{2} = 2[/tex]
[tex]x_{2} = \frac{-1 - \sqrt{25}}{2} = -3[/tex]
So
[tex]x^2 + x - 6 = (x - 2)(x - (-3)) = (x - 2)(x + 3)[/tex]
The complete factorization is:
[tex]-4x(x^2+x-6) = -4x(x - 2)(x + 3)[/tex]
Thus the correct answer is given by option d.