Bonjour,
M = - 1/2 + 7/4 x 5/9
M = -1/2 + 35/36
M = (- 1 x 18) / (2 x 18) + 35/36
M= - 18/36 + 35/36
M = 17/36
N = - 5/3 x (- 4/7 - - 9/28)
N = - 5/3 x [(- 4 x 4) / (7 x 4) + 9/28]
N = - 5/3 x (- 16/28 + 9/28)
N = - 5/3 x (- 7/28)
N = 35/84
N= (7 x 5) / (7 x 12)
N = 5/15
P = (2/7 - 3/14) x (- 5/6 - 2/9)
P = [(2 x 2) / (7 x 2) - 3/14] x [(- 5 x 3) / (6 x 3) - (2 x 2) / (9 x 2)]
P = (4/14 - 3/14) x (- 15/18 - 4/18)
P = 1/14 x (- 19/18)
P = - 19/252.
