23. 4 √4/27 = (1/9)^x.

$$\sqrt[4]{\frac{27}{9}} = (\frac{1}{9})^x$$

$$\sqrt[4]{3} = (3^{-2})^x$$

$$3^{\frac{1}{4}} = 3^{-2x}$$

$$\frac{1}{4} = -2x$$

$$x = -\frac{1}{8}$$

Ответ: $$x = -\frac{1}{8}$$