#### Answer

$y = \frac{-6(x^{2}-2)}{(x^{2}-3x+2)^{2}}$
$y = \frac{-6(x^{2}-2)}{((x-1)(x-2))^2}$

#### Work Step by Step

$y = \frac{(x+1)(x+2)}{(x-1)(x-2)}$
$y = \frac{x^{2}+3x+2}{x^{2}-3x+2}$
$y' = \frac{(x^{2}-3x+2)(2x+3) - (x^{2}+3x+2)(2x-3)}{(x^{2}-3x+2)^{2}}$
$y = \frac{-6(x^{2}-2)}{(x^{2}-3x+2)^{2}}$
$y = \frac{-6(x^{2}-2)}{((x-1)(x-2))^2}$