Répondre :
[tex] \frac{ (\frac{3}{2} - \frac{1}{3} )* \frac{13}{14} }{ \frac{4}{3} - \frac{5}{7} } = \frac{ \frac{9-2}{6} * \frac{13}{14} }{ \frac{28-15}{21} } = \frac{ \frac{7}{6}* \frac{13}{14} }{ \frac{13}{21} } = \frac{13}{12} * \frac{21}{13} = \frac{21}{12} = \frac{7}{4} [/tex]