Réponse :
3) 12 x + 4 = - 4 x - 8 ⇔ 16 x = - 12 ⇔ x = - 12/16 = - 3/4
4) 12 x + 12 = 5 x - 4 ⇔ 7 x = - 16 ⇔ x = - 16/7
5) 6 x - 10 = - 14 x - 12 ⇔ 20 x = - 2 ⇔ x = - 2/20 = - 1/10
6) 9 x + 2 = 7 x + 4 ⇔ 2 x = 2 ⇔ x = 1
7) 9 x + 6 = 10 x - 4 ⇔ - x = - 10 ⇔ x = 10
8) - 5 x + 10 = - 12 x + 1 ⇔ 7 x = - 9 ⇔ x = - 9/7
9) 5 x - 3 = 3 x + 5 ⇔ 2 x = 8 ⇔ x = 8/2 = 4
10) - 11 x - 12 = 3 x - 10 ⇔ - 14 x = 2 ⇔ x = - 2/14 = - 1/7
11) 5 x + 4 = 14 x + 5 ⇔ - 9 x = 1 ⇔ x = - 1/9
12) 6 x - 8 = 5 x + 11 ⇔ x = 19
13) 10 x - 10 = 4 x + 13 ⇔ 6 x = 23 ⇔ x = 23/6
14) - 2 x + 6 = - 7 x + 6 ⇔ 5 x = 0 ⇔ x = 0
Explications étape par étape :
