Answer :
[tex]\frac{z}{5-7}=2 \frac{1}{3} \\\\ -\frac{z}{2}=\frac{7}{3} \\\\ z=-\frac{2*7}{3} \\\\ \boxed{z=-\frac{14}{3}}[/tex]
[tex]\frac{z}{5-7}=2\frac{1}{3}\\\\\
\frac{z}{-2}=\frac{7}{3}\ \ \ |Multiply\ by\ 6\\\\
-3z=7*2\\\\
-3z=14 \ \ \ |Divide\ by\ -3\\\\
z=-\frac{14}{3}=-4\frac{2}{3}\\\\
Solution\ is\ \boxed{z=-4\frac{2}{3}}[/tex]