Bonjour :)
Réponse en explications étape par étape :
# Exercice : Soient " a = 2/3 ; b = - 1/4 ; c = 2/5 et d = - 1/2 " :
- Questions :
1. Calculer " ab + cd " :
A = (2/3 * - 1/4) + (2/5 * - 1/2)
A = - 2/12 - 2/10
A = - 1/6 - 1/5
A = - 5/30 - 6/30
A = - 11/30
2. Calculer " (a + d)/(b + c) :
B = (2/3 - 1/2)/(- 1/4 + 2/5)
B = (4/6 - 3/6)/(- 5/20 + 8/20)
B = 1/6 : 3 /20
B = 1/6 * 20/3
B = 20/18
B = (10 * 2)/(9 * 2)
B = 10/9
Voilà
