Bonjour,
37. Calculer :
[tex]a = \frac{1}{5} + \frac{3}{5} = \frac{1 + 3}{5} = \boxed{ \frac{4}{5} } [/tex]
[tex]b = \frac{6}{7} - \frac{5}{7} = \frac{6 - 5}{7} = \boxed{ \frac{1}{7} } [/tex]
[tex]c = \frac{7}{9} + \frac{2}{9} = \frac{7 + 2}{9} = \frac{9}{9} = \boxed{1} [/tex]
Bonne journée.
