can you help me with factoring for algebra 2?

it is factoring for the polynomial 4x^3 + 8x^2 - 9x - 18

Eric M2012-11-29T18:55:18Z

Favorite Answer

4x^3 + 8x^2 - 9x - 18
First pull out any common factors to all terms. In this case there are none.
Looking at the first two terms, they have 4x^2 in common.
=4x^2(x+2) - 9x - 18

The next two terms have -9 in common.
=4x^2(x+2) - 9(x +2)
=(4x^2 - 9)(x+2)

Now you can work with the Binomial (4x^2 - 9)
=(2x-3)(2x+3)(x+2)

robert s2012-11-30T02:52:03Z

First group it like this [4x^3 + 8x^2] and [9x - 18] then take GCFs from each. so... 4x^2[x + 2] - 9[x + 2] Then you set x + 2 equal to zero, as well as [4x^2 - 9] which becomes (2x-3) (2x + 3) because of difference of perfect squares. then set each of those equal to zero so x = -2, x = 3/2 and x = -3/2

Rose2012-11-30T02:45:38Z

(4x^2-9) (x+2)

Here's how
(4x^3+8x^2)-(9x-18)
4x^2(x+2)-9(x+2)
(4x^2-9) (x+2)