Question

Please help me because I got the answer wrong. ​

Answer 1

$\cfrac{1}{3}x^2~~ = ~~\cfrac{4}{27}\implies \cfrac{x^2}{3}~~ = ~~\cfrac{4}{27}\implies x^2=\cfrac{(3)4}{27}\implies x^2=\cfrac{12}{27} \implies x=\pm\sqrt{\cfrac{12}{27}} \\\\\\ x=\pm\cfrac{\sqrt{12}}{\sqrt{27}} \implies x=\pm\cfrac{\sqrt{2^2\cdot 3}}{\sqrt{3^2\cdot 3}}\implies x=\pm\cfrac{2\sqrt{3}}{3\sqrt{3}}\implies x=\pm\cfrac{2}{3}$