Bonjour,
Exercice n°51 :
a) 1/5 ÷ (-3)
= 1/5 ÷ (-3)/1 = 1/5 × 1/(-3)
= (1 × 1) / (5 × (-3))
= 1/(-15) = -1/15 ✅
b) 3/8 ÷ (-6)
= 3/8 ÷ (-6)/1 = 3/8 × 1/(-6)
= (3 × 1) / (8 × (-6))
= 3/(-48) = -1/16 ✅
c) -15/8 ÷ 5
= -15/8 ÷ 5/1 = -15/8 × 1/5
= (-15 × 1) / (8 × 5)
= -15/40 = -3/8 ✅
Bonne journée !