TeX джерело:

=\lim\limits_{x\to 2}\frac{(x+7-9)}{(1-\sqrt{x-1})(\sqrt{x+7}+3)}=\lim\limits_{x\to 2}\frac{(x-2)(1+\sqrt{x-1})}{(1-\sqrt{x-1})(1+\sqrt{x-1})(\sqrt{x+7}+3)}=\lim\limits_{x\to 2}\frac{(x-2)(1+\sqrt{x-1})}{(1-x+1)(\sqrt{x+7}+3)}=\lim\limits_{x\to 2}\frac{(x-2)(1+\sqrt{x-1})}{(2-x)(\sqrt{x+7}+3)}=