The expression can be rewritten as:

$\displaystyle\frac{{\sqrt{{{3}{x}}}+\sqrt{{{4}\cdot{3}{x}}}}}{\sqrt{{{2}}}}=\frac{{\sqrt{{{3}{x}}}+{2}\sqrt{{{3}{x}}}}}{{\sqrt{{2}}}}=\frac{{{3}\sqrt{{{3}{x}}}}}{{\sqrt{{2}}}}\usepackage{cmbright}\Huge\$