Any help to solve this one?

Answer:
Step-by-step explanation:
[tex]81^{1/2}[/tex]
[tex]3^4*{1/2}[/tex]
[tex]3^{4/2}[/tex]
[tex]3^{2}[/tex]
9
[tex]-16^{3/4}[/tex]
[tex](-2)^{4 *3/4}[/tex]
[tex](-2)^{12/4}[/tex]
[tex](-2)^{3}[/tex]
-8