<<< native
[ ESqrt
    (EGrouped [ EIdentifier "x" , ESymbol Bin "-" , ENumber "3" ])
, ESymbol Bin "+"
, ESqrt (EGrouped [ ENumber "3" , EIdentifier "x" ])
, ESymbol Bin "+"
, ESqrt
    (EFraction
       NormalFrac
       (ESqrt (EGrouped [ ENumber "3" , EIdentifier "x" ]))
       (EGrouped [ EIdentifier "x" , ESymbol Bin "-" , ENumber "3" ]))
]
>>> tex
\sqrt{x - 3} + \sqrt{3x} + \sqrt{\frac{\sqrt{3x}}{x - 3}}