\(\frac{7}{9}\cdot\frac{3}{5}=\frac{7\cdot3}{9\cdot5}=\frac{7\cdot1}{3\cdot5}=\frac{7}{15}\)
\(\frac{9}{22}\cdot55=\frac{9}{22}\cdot\frac{55}{1}=\frac{9\cdot55}{22\cdot1}=\frac{9\cdot5}{2\cdot1}=\frac{45}{2}\)
\(\frac{11}{17}:\frac{33}{34}=\frac{11}{17}\cdot\frac{34}{33}=\frac{11\cdot34}{17\cdot33}=\frac{1\cdot2}{1\cdot3}=\frac{2}{3}\)