A ray of light along $x+\sqrt{3}y=\sqrt{3}$  gets reflected upon reaching x-axis, the equation of the reflected ray is

As the slope of incident ray is  $-\frac{1}{\sqrt{3}}$ so the slope of reflected ray has to be  $\frac{1}{\sqrt{3}}$.
The point of incidence is $(\sqrt{3},0)$ . Hence the equation of reflected ray is  $y=\frac{1}{\sqrt{3}}(x-\sqrt{3})$.
$\therefore \sqrt{3}y-x=-\sqrt{3}.\therefore x-\sqrt{3}y-\sqrt{3}=0$