10. \(\dfrac{3x^3+6x^2-3x-6}{x^2-1}\)

\(\dfrac{3x^2(x+2)-3(x+2)}{(x-1)(x+1)}=\dfrac{3(x+2)(x-1)(x+1)}{(x-1)(x+1)}=3(x+2)\), при \(x\ne-1,\;x\ne1\).