Exercice sur la photo :) Merci a ceux qui m'aiderons :)

Bonjour,

a) 7(3x + 2) = x + 6
21x + 14 = x + 6
21x - x = 6 - 14
20x = - 8
x = - 8/20
x = - 0.4

b)  2(- 3.1 + x) = - 3.1 + x
- 6.2 + 2x = - 3.1 + x
 2x - x = - 3.1 + 6.2
x = 3.1

c) - 10/7 + 2x = x - 5/7
2x - x = - 5/7 + 10/7
x = 5/7