Cho \(P=\left(\dfrac{x-1}{3+\sqrt{x-1}}+\dfrac{x+8}{10-x}\right):\left(\dfrac{3\sqrt{x-1}+1}{x-3\sqrt{x-1}-1}-\dfrac{1}{\sqrt{x-1}}\right)\)
a) Rút gọn .
b) Tính giá trị P khi \(x=\sqrt{\dfrac{3+2\sqrt{2}}{3-2\sqrt{2}}}-\sqrt{\dfrac{3-2\sqrt{2}}{3+2\sqrt{2}}}\)