Bonjour
A = 2/3 - - 7/4 - 1/5
A = (2 x 20) / (3 x 20) + (7 x 15) / (4 x 15) - (1 x 12) / (5 x 12)
A = 40/60 + 105/60 - 12/60
A = 133/60
B = 3 - (5/7 - 9/14)
B = (3 x 14) / (1 x 14) - [(5 x 2) / (7 x 2) - 9/14]
B = 42/14 - (10/14 - 9/14)
B = 42/14 - 1/14
B = 41/14.
