\(a,P=\dfrac{x^2+5x+6+x^2-5x+6-2x^2-3x-6}{\left(x-2\right)\left(x+2\right)}\\ P=\dfrac{-3x+6}{\left(x-2\right)\left(x+2\right)}=\dfrac{-3\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{-3}{x+2}\\ b,P=\dfrac{-3}{3+2}=-\dfrac{3}{5}\\ c,P\in Z\Leftrightarrow x+2\inƯ\left(3\right)=\left\{-3;-1;1;3\right\}\\ \Leftrightarrow x\in\left\{-5;-3;-1;1\right\}\)


