How do you factor (2x - 3)^3 - 27(2x3)327?

1 Answer
May 9, 2015

Factoring (2x-3)^3 -27(2x3)327

Consider a related problem:
Find the solutions for (2x-3)^3 -27 = 0(2x3)327=0

(2x-3)^3 = 27(2x3)3=27

(2x-3)^3 = 3^3(2x3)3=33

2x-3 = 32x3=3

x=3x=3

So (x-3)(x3) is a factor of (2x-3)^3-27(2x3)327

Using synthetic division we can determine that
(2x-3)^3-27 = (x-3)(8x^2-12x+18)(2x3)327=(x3)(8x212x+18)

We can extract a common factor of (2)(2) from this final factor
(2x-3)^3-27 = (x-3)(2)(4x^2-6x+9)(2x3)327=(x3)(2)(4x26x+9)

Examining the discriminant of (4x^2-6x+9)(4x26x+9) reveals that there are no further factors.