Bonsoir
L = 10/7 - 7/3
L = (10 x 3) / (7 x 3) - (7 x 7) / (3 x 7)
L = 30/21 - 49/21
L = - 19/21
M = 13/3 - 9/8
M = (13 x 8) / (3 x 8) - (9 x 3) / (8 x 3)
M = 104/24 - 27/24
M = 77/24
N = 4/3 - - 7/9
N = (4 x 3) / (3 x 3) + 7/9
N = 12/9 + 7/9
N = 19/9
O = 3/2 + - 1/20
O = (3 x 10) / (2 x 10) - 1/20
O = 30/20 - 1/20
O = 29/20
P = 5/11 + 5/3
P = (5 x 3) / (11 x 3) + (5 x 11) / (3 x 11)
P = 15/33 + 55/33
P = 70/33
Q = 1/6 - 1/8
Q = (1 x 4) / (6 x 4) - (1 x 3) / (8 x 3)
Q = 4/24 - 3/24
Q = 1/24.
