\(a)\dfrac{3}{7}+\dfrac{9}{8}=\dfrac{24}{56}+\dfrac{63}{56}=\dfrac{24+63}{56}=\dfrac{87}{56}\)
\(b)\dfrac{4}{5}-\dfrac{2}{15}=\dfrac{12}{15}-\dfrac{2}{15}=\dfrac{12-2}{15}=\dfrac{10}{15}=\dfrac{2}{3}\)
\(c)\dfrac{8}{11}\times\dfrac{33}{5}=\dfrac{264}{55}\)
\(d)4:\dfrac{1}{7}=\dfrac{4}{1}\times\dfrac{7}{1}=\dfrac{28}{1}=28\)
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