a) \(\frac{6}{13} \cdot 19\frac{1}{2}\) = \(\frac{6}{13} \cdot \frac{39}{2}\) = \(\frac{6 \cdot 39}{13 \cdot 2}\) = \(\frac{3 \cdot 3}{1 \cdot 1}\) = 9
Ответ: 9