Expression: $$\sqrt [ 4 ] { \frac { - 81 } { - 16 } }$$
Fraction $\frac{-81}{-16}$ can be simplified to $\frac{81}{16}$ by removing the negative sign from both the numerator and the denominator.$$\sqrt[4]{\frac{81}{16}}$$
Calculate $\sqrt[4]{\frac{81}{16}}$ and get $\frac{3}{2}$.$$\frac{3}{2}$$