1) A=(831-532)/84
=299/84
≈ 3,56 arrondi au centième
2) 3,7 heure
=3 heure+0,7 heure
=3 heure+0,7*60 min
=3 h 42 min
3) B=(53/61-32/85)/(63/34)
=(53*85-51*32)/(51*85)*(34/63)
=(2873/4335)*(34/63)
=(17*169)/(17*255)*(34/63)
=(169/255)*(34/63)
=(169*34)/(255*63)
=5746/16065
=(17*338)/(17*945)
=338/945
