Simplifie les fractions suivantes (avec calcul): 297/120: 420/297: 594/420: 840/594: 1188/840

297/120 = 297:3/120:3 = 99/40
420/297 = 420:3/297:3 = 140/99
594/420 = 594:6/420:6 = 99/70
840/594 = 840:6/594:6 = 140/99
1188/840 = 1188:12/840:12 = 99/70