A = -1/ 20 + 4/5
A = -1/20 + 16/20
A = 15/20
A = 3/4
B = -3/4 - 2
B = -3/4 - 8/4
B = -11/4
C = 5/6 + 1/30
C = 25/30 + 1/30
C = 26/30
C = 13/15
D = 19/28 - 3/7
D = 19/28 - 12/28
D = 7/28
D = 1/4
E = 7/9 - (-2/81)
E = 63/81 + 2/81
E = 65/81
F = 31/9 - 3
F = 31/9 - 27/9
F = 4/9
La technique est simple, tu mets d’abord au même dénominateur ensuite tu fait l’opération.
