répondez svp !!!!!!!!!!!!!

Bonjour,
M : -1/2 + (7/4 x 5/9)
= -1/2 + 35/36
= -1x18 / 2x 18 + 35/36
= -18 / 36 + 35/36
= 17/36

N = -5/3 x (-4/ 7 - -9/28)
= -5/ 3 x ( -4 / 7 + 9 / 28)
= -5/3 x ( -4 x 4 / 7x4 + 9/28)
= -5/3 x (- 16/ 28 + 9/28 )
= -5/3 x -7/28
= 35 / 84
= 7x5 / 7x12
= 5/12

P = (2/ 7 - 3/14) x (-5 / 6 -2/9 )
= ( 2x2 / 7x2 - 3/14) x (-5x 3/ 6x3 - 2x2 /9x2 )
= (4/14 - 3/14 ) x (-15/ 18 - 4/18)
= 1/14 x -19/18
= -19/ 252