Answer :

[tex]x+\frac{2}{3}=\frac{11}{12}\ \ \ /-\frac{2}{3}\\\\x=\frac{11}{12}-\frac{2}{3}\\\\x=\frac{11}{12}-\frac{2\cdot4}{3\cdot4}\\\\x=\frac{11}{12}-\frac{8}{12}\\\\x=\frac{11-8}{12}\\\\x=\frac{3}{12}\\\\\underline{\underline{x=\frac{1}{4}}}[/tex]