Bonjour !
Ex 73 - b :
[tex] \frac{3}{7} + \frac{3}{4} - \frac{5}{2} - \frac{17}{8} \\ = \frac{12}{28} + \frac{21}{28} - \frac{70}{28} - \frac{17}{8} \\ = \frac{12 + 21 - 70 }{28}- \frac{17}{8} \\ = \frac{ - 37}{28} - \frac{17}{8}\\ = - \frac{296}{224} - \frac{476}{224} \\ = \frac{ - 296 - 476}{28} \\ = - \frac{772}{224} \\ = - \frac{193}{56} [/tex]
Bonne soirée
