Réponse :

Bonjour

Explications étape par étape

Exercice 1.

Equations

x + 5 = 18

x = -5 +18 = 13

2x -27 = 3

2x = +27 +3

2x = 30

x = 30/2 = 15

7x +10 = 2 -x

7x +x = -10 +2

8x = -8

x = -8/8 = -1

x/5 = 30

x = 150

(x +8)(7x -3) = 0

x +8 = 0

x = -8

7x -3 = 0

7x = 3

x = 3/7