Réponse:
[tex]a = 7 + \frac{1}{2} = \frac{14 + 1}{2} = \frac{15}{2} [/tex]
[tex]b = 4 - \frac{1}{3} = \frac{12 - 1}{3} = \frac{11}{3} [/tex]
[tex]c = \frac{3}{4} + 3 = \frac{3 + 12}{4} = \frac{15}{4} [/tex]
[tex]d = \frac{15}{7} - 2 = \frac{15 - 14}{7} = \frac{1}{7} [/tex]
