Bonjour :)
Réponse en explications étape par étape :
- Question : Calculer :
A = (5/7 + 1/4) / (6/7 - 1/2)
A = [(5 * 4 + 7 * 1) / (7 * 4)] / [(6 * 2 - 7 * 1) / (7 * 2)]
A = [(20 + 7) / 28] / [(12 - 7) / 14]
A = (27/28) / (5/14)
A = 27/28 * 14/5
A = 378/140
A= 27/10
B = (4/3 - 2/9) / (5/28 * 21/25)
B = [(4 * 9 - 3 * 2) / (3 * 9)] / (315/700)
B = [(36 - 6) / 27] / (315/700)
B = (30/27) / (315/700)
B = [(10 * 3) / (9 * 3)] / [( 9 * 35) / (20 * 35)]
B = 10/9 / 9/20
B = 10/9 * 20/9
B = 200/81
Voilà
