Answer:
its 9
Step-by-step explanation:
c. 9i.
[tex]\sqrt{-81}[/tex]
= [tex]\sqrt{-1 * 9 * 9}[/tex]
= [tex]\sqrt{-1 * 9^2}[/tex]
= [tex]9\sqrt{-1}[/tex]
The square root of -1 is the same thing as i.
= [tex]9i[/tex]
So, your answer is C.
Hope this helps!
