13. $$(\frac{1}{8})^{-2.3} = 2^x \Rightarrow x=?

$$\((\frac{1}{8})^{-2.3} = (2^{-3})^{-2.3} = 2^{(-3) \cdot (-2.3)} = 2^{6.9} = 2^x\)$$. Тогда: $$\((x = 6.9)\)$$. Ответ: $$\((x = 6.9)\)$$