1) $$\frac{x-4}{x-2} - \frac{x}{2-x} = \frac{x-4}{x-2} + \frac{x}{x-2} = \frac{x - 4 + x}{x-2} = \frac{2x - 4}{x - 2} = \frac{2(x - 2)}{x - 2} = 2$$
Ответ: $$2$$