[tex]\it a = \sqrt{12}-2\sqrt{27}=\sqrt{147}=\sqrt{4\cdot3}-2\sqrt{9\cdot3}+\sqrt{49\cdot3}=\\ \\ =2\sqrt{3}-6\sqrt{3}+7\sqrt{3}=3\sqrt3\\ \\ Ecua\c{\it t}ia\ devine\ :\\ \\ 3\sqrt3x+\dfrac{1}{3\sqrt3}=3|_{\cdot3\sqrt3} \Rightarrow 27x+1=9\sqrt3\Rightarrow 27x=9\sqrt3-1\Rightarrow \\ \\ \\ x=\dfrac{9\sqrt3-1}{27}[/tex]
