Answer
$-\frac{21}{36}$
Work Step by Step
When $x=-\frac{1}{3}$ and $z=\frac{5}{6}$:
$x^{2}-z^{2}$
$=(-\frac{1}{3})^{2}-(\frac{5}{6})^{2}$
$=[(-\frac{1}{3}\times(-\frac{1}{3})]-(\frac{5}{6}\times\frac{5}{6})$
$=(\frac{1}{3}\times\frac{1}{3})-\frac{25}{36}$
$=\frac{1}{9}-\frac{25}{36}$
$=\frac{4}{36}-\frac{25}{36}$
$=-\frac{21}{36}$
