Réponse :
[tex]-\frac{1}{3} + \frac{3}{5} = -\frac{5}{15} + \frac{9}{15} = \frac{4}{15}[/tex]
[tex]\frac{2}{1} - \frac{7}{3} = \frac{6}{3} - \frac{7}{3} = -\frac{1}{3}[/tex]
[tex]-\frac{1}{3} * \frac{3}{5} = -\frac{1}{5}[/tex]
[tex]\frac{1}{3} / -9 = -\frac{1}{3} * -\frac{1}{9} = -\frac{1}{27}[/tex]
[tex]\frac{2}{5} - \frac{1}{5}*(1 - \frac{4}{3}) = \frac{2}{5} - \frac{1}{5}* - \frac{1}{3} = \frac{2}{5} + \frac{1}{15} = \frac{6}{15} + \frac{1}{15} = \frac{7}{15}[/tex]
[tex](1 - \frac{7}{6}) / (1 + \frac{7}{6}) = -\frac{1}{6} / \frac{13}{6} = -\frac{1}{6} * \frac{6}{13} = -\frac{1}{13}[/tex]
