Bonjour ! J'espère vous aider !
Réponse :
n°86 :
a) 3/48 + 5/6 = 3/48 + 5*8/6*8 = 3/48 + 40/48 = 43/48
b) 1/7 - 11/35 = 1*5/7*5 - 11/35 = 5/35 - 11/35 = -6/35
n°87 :
A = -1/20 + 4/5
A = -1/20 + 4*4/5*4
A = -1/20 + 16/20
A = 15/20
A = 3/4
B = -3/4 - 2
B = -3/4 - 2/1
B = -3/4 - 2*4/1*4
B = -3/4 - 8/4
B = -11/4
C = 5/6 + 1/30
C = 5*5/6*5 + 1/30
C = 25/30 + 1/30
C = 26/30
C = 13/15
D = 19/28 - 3/7
D = 19/28 - 3*4/7*4
D = 19/28 - 12/28
D = 7/28
D = 1/4
E = 7/9 - -2/81
E = 7/9 + 2/81
E = 7*9/9*9 + 2/81
E = 63/81 + 2/81
E = 65/81
F = 31/9 - 3
F = 31/9 - 3/1
F = 31/9 - 3*9/1*9
F = 31/9 - 27/9
F = 4/9
