Répondre :
s = -4/15 + (60/30+7/-30)
= -4/15 +67/-30
= -8/30 +67/-30
= 75/30 =5/2
T = 3 + (10/14-9/14)
= 3 + 1/14
=42/14 = 1/14
=43/14
u = 7/4 - ( -5/40-12/40)
= 7/4- (-17/40)
=70/40 - (-17/40)
= 87/40
= -4/15 +67/-30
= -8/30 +67/-30
= 75/30 =5/2
T = 3 + (10/14-9/14)
= 3 + 1/14
=42/14 = 1/14
=43/14
u = 7/4 - ( -5/40-12/40)
= 7/4- (-17/40)
=70/40 - (-17/40)
= 87/40