4) = -18 2

4) $$\frac{6^x}{2} - 6^x = -18$$

$$6^x \cdot (\frac{1}{2} - 1) = -18$$

$$6^x \cdot (-\frac{1}{2}) = -18$$

$$6^x = 36$$

$$6^x = 6^2$$

$$x = 2$$

Ответ: 2