Réponse:
Bonsoir
1.
[tex] \frac{1}{n} + \frac{1}{2n} + \frac{1}{3n} + \frac{1}{6n} = \frac{6}{6n} + \frac{3}{6n} + \frac{2}{6n} + \frac{1}{6n} [/tex]
[tex] = \frac{12}{6n} = \frac{2}{n} [/tex]
2.
n = 11
[tex] \frac{2}{11} = \frac{1}{11} + \frac{1}{22} + \frac{1}{33} + \frac{1}{66} [/tex]
