You want to make sure to factor each equation as much as you can first.
So just focus on the numerator first. [tex]x^3-6x^2+8x[/tex]
To factor the numerator:
[tex](x)(x^2-6x+8)[/tex] factor out an x
[tex](x)(x-4)(x-2)[/tex] factor out the rest completely.
Now for the denominator: [tex]-4x^2+4x+24[/tex]
[tex](-4)(x^2+x+6)[/tex] factor out a -4
[tex](-4)(x+3)(x-2)[/tex] factor out the rest.
This leaves you with:
[tex]\frac{(x)(x-4)(x-2)}{(-4)(x+3)(x-2)}[/tex]
Then you can simplify:
[tex]\frac{(x)(x-4)}{(-4)(x+3)} [/tex]
I'm not sure what you're supposed to find exactly, so if you need more help you can ask me (:
