\(\dfrac{7}{15}+\dfrac{4}{5}\)
\(=\dfrac{7}{15}+\dfrac{12}{15}\)
\(=\dfrac{19}{15}\)
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\(\dfrac{35}{28}-\dfrac{48}{64}\)
\(=\dfrac{2240}{1792}-\dfrac{1344}{1792}\)
\(=\dfrac{896}{1792}=\dfrac{1}{2}\)
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\(\dfrac{10}{13}:\dfrac{3}{4}\)
\(=\dfrac{10}{13}\)x\(\dfrac{4}{3}\)
\(=\dfrac{40}{39}\)