б) \(\frac{2}{3}\) \(\cdot\) (\(\frac{9}{8}\) - \(\frac{3}{4}\)) = \(\frac{2}{3}\) \(\cdot\) (\(\frac{9}{8}\) - \(\frac{6}{8}\)) = \(\frac{2}{3}\) \(\cdot\) \(\frac{3}{8}\) = \(\frac{2 \cdot 3}{3 \cdot 8}\) = \(\frac{6}{24}\) = \(\frac{1}{4}\). Ответ: \(\frac{1}{4}\)