Step-by-step explanation:
Hey, there!!
I hope you mean,
[tex] \frac{ - 1}{2} \: means \: \sqrt{} [/tex]
and
[tex]36 = {6}^{2} \: and \: 81 = {9}^{2} [/tex]
[tex]so \: \: \sqrt{ \frac{ {6}^{2} }{ {9}^{2} } } [/tex]
[tex]or \: ( { \frac{ {6}^{2} }{ {9}^{2} }) }^{ \frac{ - 1}{2} } [/tex]
so, the answer is 6/9 or, 2/3.
Hope you are searching this...