1. ## factoring with brackets

Hi all;
I can factor (x-3)^4 + 2(x-3)^2 -8 to give (x^2 - 6x +13)(x^2 - 6x +7)

What I need is more practice with this type of factoring so does anyone know of any websites that contain these typs of problems and indeed any good books on factoring and logarithums?

Thanks.

2. Here it's easiest to use a dummy variable to turn it into an easier quadratic.

Let $X = (x - 3)^2$ to give

$=X^2 + 2X - 8$

$=(X + 4)(X - 2)$

$= [(x - 3)^2 + 4][(x - 3)^2 - 2]$

$= (x^2 - 6x + 9 + 4)(x^2 - 6x + 9 - 2)$

$= (x^2 - 6x + 13)(x^2 - 6x + 7)$.

3. Got it thanks,Anyone help with websites or books.