Réponse:
Bonjour
Explications étape par étape:
A = -1/2 + 9 ÷ -6/7 - 2
= -1/2 + 18/2 ÷ -6/7 - 14/7
= 17/2 ÷ -20/7
= 17/2 × 7/-20
A = 119/-40
B = -9/4 × (-3/2 + -3/5)
= -9/4 × (-15/10 + -6/10)
= -9/4 × -21/10
B = 189/40
C = -21/2 - -5/2 ÷ 3/2
= -21/2 + 10/6
= 63/6 + 10/6
C = 73/6
