bonjour
a = 5/6 - 2/6 = 3/6 = 1/2
b = 21/27 - 1/27 = 20/27
c = 80/50 + 23/50 = 103/50
d = 45/15 - 35/15 = 10 /15 = 2/3
e = 4/11 + 22/11 = 26/11
f = - 8/91 - 13/91 = - 21/91 = -3/13
G = 20/8 - 90/8 + 2/8 = - = - 68/8 = - 17/2 ( pas sûre du signe car - - ?)
H = 196/49 - 5/49 - 56/49 = 135/49