C, and D
1) We're told that the original equation is:
[tex]v^2=\frac{25}{81}[/tex]
2) Then let's calculate it taking the square root on both sides:
[tex]\begin{gathered} \sqrt[]{v^2}=\pm\sqrt[]{\frac{25}{81}} \\ v=-\frac{5}{9},\text{ }\frac{5}{9} \end{gathered}[/tex]
3) So we can state that the answer is C, and D
