a,b: \(P=\dfrac{3x-3-2x-2}{\left(x+1\right)\left(x-1\right)}\cdot\dfrac{\left(x-1\right)\left(x+1\right)}{x+2}=\dfrac{x-5}{x+2}\)
Khi x=5 thì \(P=\dfrac{5-5}{5+2}=0\)
c: Để P nguyên thì x+2-7 chia hết cho x+2
=>\(x+2\in\left\{1;-1;7;-7\right\}\)
=>\(x\in\left\{-1;-3;5;-9\right\}\)