Réponse :
Bonsoir
Explications étape par étape
E = 11/20 - 7/4 ÷ (-15)/16
E = 11/20 -7/4 * (-16)/15
E = 11/20 - ( 7*(-4)*4))/(4*15)
E = 11/20 - (-28)/15
E = 11/20 + 28/15
E = (11*3)/(20*3) + (28*4)/(15*4)
E = 33/60 + 112/60
E = 145/60
E = (5*29)/(5*12)
E = 29/12
F = -8/21 * 15/4 ÷ 5/24
F = -8/21 * 15/4 * 24/5
F = (-4*2*5*3*2*12)/(7*3*2*2*5)
F = -48/7