Réponse :
Explications étape par étape
Bonsoir
4/3-7/5-(3/5-5/7)
= 4/3 - 7/5 - [(3 x 7)/(5 x 7) - (5 x 5)/(7 x 5)]
= 4/3 - 7/5 - (21/35 - 25/35)
= 4/3 - 7/5 - (-4/35)
= 4/3 - 7/5 + 4/35
= 4/3 - (7 x 7)/(5 x 7) + 4/35
= 4/3 - 49/35 + 4/35
= 4/3 - 45/35
= 4/3 - (9 x 5)/(7 x 5)
= 4/3 - 9/7
= (4 x 7)/(3 x 7) - (9 x 3)/(7 x 3)
= 28/21 - 27/21
= 1/21
