Giải thích các bước giải:
Ta có :
$M=\dfrac{x-11}{\sqrt{x-2}-3}$
$\to M=\dfrac{(x-11)(\sqrt{x-2}+3)}{(\sqrt{x-2}+3)(\sqrt{x-2}-3)}$
$\to M=\dfrac{(x-11)(\sqrt{x-2}+3)}{x-2-9}$
$\to M=\dfrac{(x-11)(\sqrt{x-2}+3)}{x-11}$
$\to M=\sqrt{x-2}+3$
$\to M=\sqrt{23-12\sqrt{3}-2}+3$
$\to M=\sqrt{21-12\sqrt{3}}+3$