a. \(\dfrac{5}{3};\dfrac{17}{5};\dfrac{9}{7}\)
b. \(\dfrac{9}{18}=\dfrac{9\div9}{18\div9}=\dfrac{1}{2}\)
\(\dfrac{120}{240}=\dfrac{120\div120}{240\div120}=\dfrac{1}{2}\)
\(\dfrac{33}{11}=\dfrac{33\div11}{11\div11}=3\left(\dfrac{3}{1}\right)\)
\(\dfrac{45}{63}=\dfrac{45\div9}{63\div9}=\dfrac{5}{7}\)