Aider moi svp besoins d'aide merci Exercice 5

[tex] \frac{3*4}{7*4} - \frac{21}{7*4} = \frac{12-21}{28} = \frac{-9}{28} [/tex]

[tex] \frac{5}{4}: ( \frac{4*2- 1*3}{3*2})= \frac{5}{4}: ( \frac{8- 3}{6})= \frac{5}{4}: ( \frac{5}{6})= \frac{5}{4}* ( \frac{6}{5})= \frac{6}{4} =\frac{3}{2}[/tex]