Répondre :
B = (3/5 -1/4) = 12/20 - 5/20 = 7/20 = 7/20 X 3/5 = 21/100
1 +2/3 3/3 +2/3 5/3
C = -5/7 + 5/21 X 9/25 =
-5/7+ 45/525 =
-5/7 +3/35
-25/35 + 3/35
-22/35
1 +2/3 3/3 +2/3 5/3
C = -5/7 + 5/21 X 9/25 =
-5/7+ 45/525 =
-5/7 +3/35
-25/35 + 3/35
-22/35