Bonjour
A)Simplifier le plus possible :
1)28/12 = (4 x 7) / (4 x 3) = 7/3
2)34/22 = (2 x 17) / (2 x 11) = 17/11
3)25/45 = (5 x 5) / (5 x 9) = 5/9
4)24/20 = (4 x 6) / (4 x 5) = 6/5
B) Calculer:
1) 2/7+9/7 = 11/7
2) 2/9+8/9 = 10/9
3) 18/5-11/5 = 7/5
4)12/19 -1/19 = 11/19.