2) \frac{3}{26}x + \frac{8}{13} x;

2) $$\frac{3}{26}$$x + $$\frac{8}{13}$$ x = x($$\frac{3}{26}$$ + $$\frac{8}{13}$$) = x($$\frac{3}{26}$$ + $$\frac{8 \cdot 2}{13 \cdot 2}$$) = x($$\frac{3}{26}$$ + $$\frac{16}{26}$$) = x$$\cdot$$\frac{3+16}{26}$$ = x$$\cdot$$\frac{19}{26}$$ = $$\frac{19}{26}$$x

Ответ: $$\frac{19}{26}$$x