Bonjour,
M= 21/24 - 2/24 = 19/24
N= -16/36 + 15/36 = -1/36
P= -21/18 - 30/18 +4/18 = -47/18
Q=
20/15 + 2/15 -( 12/16 - 2/16)
= 22/15 - 10/16
= 22/15 - 5/8
= 22/15 * 8/8 - 5/8 * 15/15
=176/120 - 75/ 120
= 101/120
