в) 2x x 5x-10 x-2.

в) $$ \frac{2x}{5x-10} + \frac{x}{x-2} = \frac{2x}{5(x-2)} + \frac{x}{x-2} = \frac{2x + 5x}{5(x-2)} = \frac{7x}{5(x-2)} $$

Ответ: $$ \frac{7x}{5(x-2)} $$