Simplify each radical expression. Use absolute value symbols when needed. (13 is the question number)

[tex]\sqrt{\cfrac{9x^4}{36}}\implies \sqrt{\cfrac{3^2 (x^2)^2}{6^2}}\implies \sqrt{\cfrac{(3x^2)^2}{6^2}}\implies \sqrt{\left( \cfrac{3x^2}{6} \right)^2}\implies \cfrac{3x^2}{6}\implies \cfrac{x^2}{2}[/tex]