a: \(\dfrac{4\cdot7}{9\cdot32}=\dfrac{1}{8}\cdot\dfrac{7}{9}=\dfrac{7}{72}\)
b: \(\dfrac{3\cdot21}{14\cdot15}=\dfrac{63}{210}=\dfrac{3}{10}\)
c: \(\dfrac{9\cdot6-9\cdot3}{18}=\dfrac{9\cdot3}{18}=\dfrac{3}{2}\)
d: \(\dfrac{17\cdot5-17}{3-20}=\dfrac{17\cdot4}{-17}=-4\)
a) \(\dfrac{4.7}{9.32} = \dfrac{4.7}{9.8.4} = \dfrac{7}{9.8} = \dfrac{7}{72} \)
b) \(\dfrac{3.21}{14.15} = \dfrac{3.3.7}{2.7.3.5} = \dfrac{3}{2.5} =\dfrac{3}{10} \)
c) \(\dfrac{9.6-9.3}{18} = \dfrac{9.(6-3)}{9.2} = \dfrac{6-3}{2} = \dfrac{3}{2}\)
d) \(\dfrac{17.5-17}{3-20} = \dfrac{17.(5-1)}{-17} = \dfrac{17.(5-1)}{17.(-1)} =\) \(\dfrac{4}{-1} = -4\)