1) a) \(\frac{9}{18}\cdot \frac{26}{27}\);

a) \(\frac{9}{18}\cdot \frac{26}{27} = \frac{1}{2} \cdot \frac{26}{27} = \frac{1 \cdot 26}{2 \cdot 27} = \frac{26}{54} = \frac{13}{27}\)
Ответ: \(\frac{13}{27}\)