[tex] \frac{1}{2} \times {81}^{ \frac{1}{4} } \times {64}^{ \frac{1}{2} } [/tex]
[tex] \frac{1}{2} \times ( {9}^{2} {)}^{ \frac{1}{4} } \times ( {8}^{2} {)}^{ \frac{1}{2} } [/tex]
[tex] \frac{1}{2} \times (9 {)}^{ \frac{2}{4} } \times {8}^{ \frac{2}{2} } [/tex]
[tex] \frac{1}{2} \times ( {3}^{2} {)}^{ \frac{2}{4} } \times 8[/tex]
[tex] \frac{1}{2} \times {3}^{ \frac{4}{4} } \times 8[/tex]
[tex] \frac{1}{2} \times 3 \times 8[/tex]
[tex] \frac{1 \times 3 \times 8}{2} [/tex]
[tex] \frac{24}{2} \to\boxed{\bf\blue{12}}[/tex]