Bonjour,
Résoudre l'équation:
-7(3 + 3a) = 7(a + 8)
-7*3 + (-7)*3a = 7(a + 8)
-21 - 21a = 7(a + 8)
-21a - 21 = 7(a + 8)
-21a - 21 = 7*a + 7*8
-21a - 21 = 7a + 56
-21a - 21 + 21 = 7a + 56 + 21
-21a = 7a + 77
-21a - 7a = 7a + 77 - 7a
-28a = 77
28a = -77
a = -77/28
a = -11/4
✅
* = multiplication
Bonne journée
