6. 12 - 6 11/26

6. $$12 - 6 \frac{11}{26} = 11 \frac{26}{26} - 6 \frac{11}{26} = (11 - 6) + (\frac{26}{26} - \frac{11}{26}) = 5 + \frac{26-11}{26} = 5 \frac{15}{26}$$

Ответ: $$5 \frac{15}{26}$$