2.
$\lim\limits_{x\to 1}\dfrac{\sqrt{2x+2}-2+\sqrt{5x+4}-3}{x-1}$
$=\lim\limits_{x\to 1}\Big( \dfrac{2x+2-4}{(x-1)(\sqrt{2x+2}+2) } +\dfrac{5x+4-9}{(x-1)(\sqrt{5x+4}+3)} \Big)$
$=\lim\limits_{x\to 1}\Big( \dfrac{2}{\sqrt{2x+2}+2} +\dfrac{5}{\sqrt{5x+4}+3} \Big)$
$=\dfrac{2}{\sqrt{2+2}+2}+\dfrac{5}{\sqrt{5+4}+3}$
$=\dfrac{4}{3}$
5.
Bạn xem lại tử số (hoặc $x\to 6^-$ hay $x\to 6^+$)