Answer :

Like this?

[tex] \frac{2}{3} + \frac{1x{4} = \frac{1}{3} [/tex]

[tex] \frac{x}{4} = - \frac{1}{3} [/tex]

x = 4 : -1/3

[tex]x =-\frac{3}{4}[/tex]

*correct me if i wrong
^_^
Pixie
2/3 + 1/4x = 1/3

⇒1/4x = 1/3 - 2/3

⇒1/4x = -1/3

⇒-3 = 4x 

⇒ x = - 3/4