Répondre :
Bonjour,
7x + 3 = 10x - 9
⇔ 10x - 7x = 3 + 9
⇔ 3x = 12
⇔ x = 12/3 = 4
-3x + 2(x + 4) = 0
⇔ -3x + 2x + 8 = 0
⇔ -x + 8 = 0
⇔ x = 8
5(y - 2) = 5
⇔ 5y - 10 = 5
⇔ 5y = 10 + 5 = 15
⇔ y = 15/5 = 3
Bonjour,
7x + 3 = 10x - 9
⇔ 10x - 7x = 3 + 9
⇔ 3x = 12
⇔ x = 12/3 = 4
-3x + 2(x + 4) = 0
⇔ -3x + 2x + 8 = 0
⇔ -x + 8 = 0
⇔ x = 8
5(y - 2) = 5
⇔ 5y - 10 = 5
⇔ 5y = 10 + 5 = 15
⇔ y = 15/5 = 3